No two cues are alike: Depth of learning during infancy is dependent on what orients attention

Human infants develop a variety of attentional mechanisms that allow them to extract relevant information from a cluttered multimodal world. We know that both social and nonsocial cues shift infants’ attention, but not how these cues differentially affect learning of multimodal events. Experiment 1 used social cues to direct 8- and 4-month-olds’ attention to two audiovisual events (i.e., animations of a cat or dog accompanied by particular sounds) while identical distractor events played in another location. Experiment 2 directed 8-month-olds’ attention with colorful flashes to the same events. Experiment 3 measured baseline learning without attention cues both with the familiarization and test trials (no cue condition) and with only the test trials (test control condition). The 8-month-olds exposed to social cues showed specific learning of audiovisual events. The 4-month-olds displayed only general spatial learning from social cues, suggesting that specific learning of audiovisual events from social cues may be a function of experience. Infants cued with the colorful flashes looked indiscriminately to both cued locations during test (similar to the 4-month-olds learning from social cues) despite attending for equal duration to the training trials as the 8-month-olds with the social cues. Results from Experiment 3 indicated that the learning effects in Experiments 1 and 2 resulted from exposure to the different cues and multimodal events. We discuss these findings in terms of the perceptual differences and relevance of the cues.     

The magic spell of language: linguistic categories and their perceptual consequences

Language is a tool that directs attention to different aspects of reality. Using participants from the same linguistic community, the authors demonstrate in 4 studies that metasemantic features of linguistic categories influence basic perceptual processes. More specifically, the hypothesis that abstract versus concrete language leads to a more global versus local perceptual focus was supported across 4 experiments, in which participants used (Experiment 1) or were primed either supraliminally (Experiments 2 and 3) or subliminally (Experiment 4) with abstract (adjectives) or concrete (verbs) terms. Participants were shown to display a global versus specific perceptual focus (Experiments 1 and 4), more versus less inclusiveness of categorization (Experiments 2 and 3), and incorporation of more rather than less contextual information (Experiment 3). The implications of this new perspective toward the language-perception interface are discussed in the context of the general linguistic relativity debate.     

Evidence for a confidence–accuracy relationship in memory for same- and cross-race faces

Discrimination accuracy is usually higher for same- than for cross-race faces, a phenomenon known as the cross-race effect (CRE). According to prior research, the CRE occurs because memories for same- and cross-race faces rely on qualitatively different processes. However, according to a continuous dual-process model of recognition memory, memories that rely on qualitatively different processes do not differ in recognition accuracy when confidence is equated. Thus, although there are differences in overall same- and cross-race discrimination accuracy, confidence-specific accuracy (i.e., recognition accuracy at a particular level of confidence) may not differ. We analysed datasets from four recognition memory studies on same- and cross-race faces to test this hypothesis. Confidence ratings reliably predicted recognition accuracy when performance was above chance levels (Experiments 1, 2, and 3) but not when performance was at chance levels (Experiment 4). Furthermore, at each level of confidence, confidence-specific accuracy for same- and cross-race faces did not significantly differ when overall performance was above chance levels (Experiments 1, 2, and 3) but significantly differed when overall performance was at chance levels (Experiment 4). Thus, under certain conditions, high-confidence same-race and cross-race identifications may be equally reliable.     

The return of object-based attention: selection of multiple-region objects

Objects can control the focus of attention, allowing features on the same object to be selected more easily than features on different objects. In the present experiments, we investigated the perceptual processes that contribute to such object-based attentional effects. Previous research has demonstrated that object-based effects occur for single-region objects but not for multiple-region objects under some conditions (Experiment 1, Watson & Kramer, 1999). Such results are surprising, because most objects in natural scenes are composed of multiple regions. Previous findings could therefore limit the usefulness of an object-based selection mechanism. We explored the generality of these single-region selection results by manipulating the extent to which different (i.e., multiple) regions of a single object perceptually grouped together. Object-based attentional effects were attenuated when multiple regions did not group into a single perceptual object (Experiment 1). However, when multiple regions grouped together based on (1) edge continuation (Experiments 2 and 3) or (2) part and occlusion cues (Experiment 4), we observed object-based effects. Our results suggest that object-based attention is a robust process that can select multiple-region objects, provided the regions of such objects cohere on the basis of perceptual grouping cues.     

Perceptual selectivity is task dependent: The pop-out effect poops out

An attempt was made to determine why evidence for perceptual selectivity based on conceptual category (e.g., digits vs. letters) has been found in some experiments but not in others. Experiments using the partial-report paradigm find no partial-report superiority when the report is cued by category, whereas, in recent visual search studies, evidence for perceptual selectivity has been obtained for arrays containing a single item that was categorically different from the other items (e.g., a digit among letters). Using a search task, Experiment 1 investigated the possibility that the number of categorically different items in the arrays could be a determinant of selectivity. One, two, or three digits and a variable number of letters were presented on each trial, and subjects determined if a particular digit was present. No evidence of selectivity was obtained, even for the one-digit condition. Experiment 2 verified this result, and Experiment 3 extended the failure of selectivity to a search task in which the possible targets differed in color from the distractor items. In Experiment 4, subjects counted the number of digits or red letters in arrays in which black letters were the distractor items. The counting task was used to eliminate the requirement in our previous tasks that the subjects search forspecific items. Evidence was obtained in the counting task for selectivity based on the color difference but not on the categorical difference. The color stimuli used in the counting task were essentially the same as those that did not yield any evidence of selectivity in the search task. The results suggest that task demands are an important determinant of whether or not perceptual selectivity will occur.     

The properties of object representations constructed during visual search in natural scenes

To investigate properties of object representations constructed during a visual search task, we manipulated the proportion of trials/task within a block: In a search-frequent block, 80% of trials were search tasks; remaining trials presented a memory task; in a memory-frequent block, this proportion was reversed. In the search task, participants searched for a toy car (Experiments 1 and 2) or a T-shape object (Experiment 3). In the memory task, participants had to memorize objects in a scene. Memory performance was worse in the search-frequent block than in the memory-frequent block in Experiments 1 and 3, but not in Experiment 2 (token change in Experiment 1; type change in Experiments 2 and 3). Experiment 4 demonstrated that lower performance in the search-frequent block was not due to eye-movement behaviour. Results suggest that object representations constructed during visual search are different from those constructed during memorization and they are modulated by type of target.     

What colour is the car? Implicit memory for colour information in children

Three experiments were conducted to examine age-related differences in colour memory. In Experiment 1, preschool age and elementary school age children were given a conceptual test of implicit colour memory (a colour-choice task). They were presented with the names or achromatic versions of previously studied coloured line drawings and asked to select an appropriate colour. Significant priming could be demonstrated: The children chose the previously seen colours more often than was expected by chance. Equivalent priming was found for both versions (pictorial and verbal) suggesting that colour priming may be conceptually mediated. Moreover, colour priming proved to be age invariant. Experiment 2 replicated and extended this finding by using a wider age group (preschool, elementary school, and young adults) and by giving a perceptual implicit task (picture identification) in addition to a verbal colour-choice task. Colour did not affect priming in the perceptual task. Whereas priming showed no developmental change, agerelated improvements were observed on an explicit colour memory task that differed only in the test instructions from the implicit colour-choice task (Experiments 2 and 3). Taken together, the results suggest that implicit colour memory may be mediated by conceptual processes that are age invariant.     

Rats’ anticipation of current and future trial outcomes in the ordered RNR/RNN serial pattern task

In the ordered RNR/RNN serial pattern task, rats often reduce their running speeds on trial 2 less within the RNR than within the RNN series. Initially, investigators (Capaldi, 1985; Capaldi et al., 1983) considered this trial 2 differential speed effect evidence for rats’ anticipation of inter-trial outcomes within each series. Later findings, however, suggest that this effect reflects some generalization of the ordinal position of trial 3 (Burns et al., 1986) or its similar runway cues during trial 2 (Capaldi et al., 1999). To test these generalization hypotheses, we made trial 2 more distinct from trial 3 in each series by forcing rats to alternate runways in a T-maze only on the last trial rather than on trial 2 in each series in Experiment 1, or by forcing rats to alternate runways between trials rather than to run down the same runway on all trials within each series in Experiment 2. Although enhancing the distinctiveness between these trials reduced the trial 2 differential speed effect, extensive training failed to eliminate it. Therefore, this residual difference between trial 2 speeds could reflect rats’ anticipation of trial 3 outcomes during trial 2 as originally proposed by Capaldi (1985) Experiment 3 was designed to determine whether we could enhance rats’ final trial outcome expectancies during trial 2 by making different trial 2 choices distinctive cues for each trial 3 outcome. The trial 2 speed effect was greater when rats were forced to alternate over all trials only within one of the series than when they were sometimes forced to do so in either series. Post-training probe tests revealed that both series position and the relevant within-series runway events contributed to this enhanced anticipation of trial 3 outcomes.     

Changing within-trial array location and target object position enhances rats’ (Rattus norvegicus) missing object recognition accuracy

Six rats were trained to find a previously missing target or 'jackpot' object in a square array of four identical or different objects (the test segment of a trial) after first visiting and collecting sunflower seeds from under the other three objects (the study segment of a trial). During training, objects' local positions within the array and their global positions within the larger foraging array were varied over trials but were not changed between segments within a trial. Following this training, rats were tested on their accuracy for finding the target object when a trial's test array was sometimes moved to a different location in the foraging arena or when the position of the target object within the test array had been changed. Either of these manipulations initially slightly reduced rats' accuracy for finding the missing object but then enhanced it. Relocating test arrays of identical objects enhanced rats' performance only after 10-min inter-segment intervals (ISIs). Relocating test arrays of different objects enhanced rats' performance only after 2-min ISIs. Rats also improved their performance when they encountered the target object in a new position in test arrays of different objects. This enhancement effect occurred after either 2- or 30-min ISIs. These findings suggest that rats separately retrieved a missing (target) object's spatial and non-spatial information when they were relevant but not when they were irrelevant in a trial. The enhancement effects provide evidence for rats' limited retrieval capacity in their visuo-spatial working memory.     

Perceptual processes in matching and recognition of complex pictures

The role of perceptual feature sampling in speeded matching and recognition was explored in 4 experiments. Experiments 1-3 involved a perceptual matching task with pictures of various objects and scenes. In Experiments 2 and 3, same-different judgments were given under time pressure. The main objective of the matching task was to obtain measures of the perceptual processing rates of different object features. Experiment 4 was an old-new recognition experiment, in which the same stimuli as those in the matching task were used. Response signals were used to limit processing time in the recognition task. The results demonstrated that it is possible to predict speeded recognition performance from performance in perceptual matching. A simple stochastic feature-sampling model provides a unified account of the data from the 4 experiments.     

Spatial distance effects on incremental semantic interpretation of abstract sentences: Evidence from eye tracking

A large body of evidence has shown that visual context information can rapidly modulate language comprehension for concrete sentences and when it is mediated by a referential or a lexical-semantic link. What has not yet been examined is whether visual context can also modulate comprehension of abstract sentences incrementally when it is neither referenced by, nor lexically associated with, the sentence. Three eye-tracking reading experiments examined the effects of spatial distance between words (Experiment 1) and objects (Experiment 2 and 3) on participants’ reading times for sentences that convey similarity or difference between two abstract nouns (e.g., ‘Peace and war are certainly different...’). Before reading the sentence, participants inspected a visual context with two playing cards that moved either far apart or close together. In Experiment 1, the cards turned and showed the first two nouns of the sentence (e.g., ‘peace’, ‘war’). In Experiments 2 and 3, they turned but remained blank. Participants’ reading times at the adjective (Experiment 1: first-pass reading time; Experiment 2: total times) and at the second noun phrase (Experiment 3: first-pass times) were faster for sentences that expressed similarity when the preceding words/objects were close together (vs. far apart) and for sentences that expressed dissimilarity when the preceding words/objects were far apart (vs. close together). Thus, spatial distance between words or entirely unrelated objects can rapidly and incrementally modulate the semantic interpretation of abstract sentences.     

Mood-dependent retrieval in visual long-term memory: dissociable effects on retrieval probability and mnemonic precision

Although memories are more retrievable if observers’ emotional states are consistent between encoding and retrieval, it is unclear whether the consistency of emotional states increases the likelihood of successful memory retrieval, the precision of retrieved memories, or both. The present study tested visual long-term memory for everyday objects while consistent or inconsistent emotional contexts between encoding and retrieval were induced using background grey-scale images from the International Affective Picture System (IAPS). In the study phase, participants remembered colours of sequentially presented objects in a negative (Experiment 1a) or positive (Experiment 2a) context. In the test phase, participants estimated the colours of previously studied objects in either negative versus neutral (Experiment 1a) or positive versus neutral (Experiment 2a) contexts. Note, IAPS images in the test phase were always visually different from those initially paired with the studied objects. We found that reinstating negative context and positive context at retrieval resulted in better mnemonic precision and a higher probability of successful retrieval, respectively. Critically, these effects could not be attributed to a negative or positive context at retrieval alone (Experiments 1b and 2b). Together, these findings demonstrated dissociable effects of emotion on the quantitative and qualitative aspects of visual long-term memory retrieval.     

Illusory conjunctions of forms, objects, and scenes during rapid serial visual search

"Temporal migration" describes a situation in which subjects viewing rapidly presented stimuli (e.g., 9-20 items/s) confidently report a target element as having been presented in the same display as a previous or following stimulus in the sequence. Four experiments tested a short-term buffer model of this phenomenon. Experiments 1 and 4 tested the hypothesis that subjects' errors are due to the demands of the verbal report procedure rather than to perceptual integration. In Experiment 1, 12 color objects were presented at a rate of 9/s. Prior to each sequence, an object was named and subjects responded "yes" or "no" to indicate whether the target element (a black frame) occurred with that object. Consistent with the perceptual hypothesis, the yes/no procedure yielded the same results as the verbal report procedure. Experiment 2 tested the hypothesis that the direction of migration depends on "frame" detection time. Results showed that reaction time to frame detection was significantly faster in trials in which subjects reported the frame on a preceding rather than a following picture. Experiments 3 and 4 used the standard naming procedure and the yes/no procedure to test temporal migration using more complex, interrelated stimuli (objects and scenes). Implications for the use of the temporal migration effect to study visual integration within eye fixations are discussed.     

Curious Objects: How Visual Complexity Guides Attention and Engagement

Some things look more complex than others. For example, a crenulate and richly organized leaf may seem more complex than a plain stone. What is the nature of this experience—and why do we have it in the first place? Here, we explore how object complexity serves as an efficiently extracted visual signal that the object merits further exploration. We algorithmically generated a library of geometric shapes and determined their complexity by computing the cumulative surprisal of their internal skeletons—essentially quantifying the “amount of information” within each shape—and then used this approach to ask new questions about the perception of complexity. Experiments 1–3 asked what kind of mental process extracts visual complexity: a slow, deliberate, reflective process (as when we decide that an object is expensive or popular) or a fast, effortless, and automatic process (as when we see that an object is big or blue)? We placed simple and complex objects in visual search arrays and discovered that complex objects were easier to find among simple distractors than simple objects are among complex distractors—a classic search asymmetry indicating that complexity is prioritized in visual processing. Next, we explored the function of complexity: Why do we represent object complexity in the first place? Experiments 4–5 asked subjects to study serially presented objects in a self-paced manner (for a later memory test); subjects dwelled longer on complex objects than simple objects—even when object shape was completely task-irrelevant—suggesting a connection between visual complexity and exploratory engagement. Finally, Experiment 6 connected these implicit measures of complexity to explicit judgments. Collectively, these findings suggest that visual complexity is extracted efficiently and automatically, and even arouses a kind of “perceptual curiosity” about objects that encourages subsequent attentional engagement.     

The effect of inversion on 3- to 5-year-olds’ recognition of face and nonface visual objects

This study compared the effect of stimulus inversion on 3- to 5-year-olds’ recognition of faces and two nonface object categories matched with faces for a number of attributes: shoes (Experiment 1) and frontal images of cars (Experiments 2 and 3). The inversion effect was present for faces but not shoes at 3 years of age (Experiment 1). Analogous results were found for boys when faces were compared with frontal images of cars. For girls, stimulus inversion impaired recognition of both faces and cars at 3 to 4 years of age, becoming specific to faces only at 5 years of age (Experiments 2 and 3). Evidence demonstrates that the ability to extract the critical cues that lead to adults’ efficient face recognition is selectively tuned to faces during preschool years.     

Approach motivation as incentive salience: perceptual sources of evidence in relation to positive word primes

Four experiments (total N = 391) examined predictions derived from a biologically based incentive salience theory of approach motivation. In all experiments, judgments indicative of enhanced perceptual salience were exaggerated in the context of positive, relative to neutral or negative, stimuli. In Experiments 1 and 2, positive words were judged to be of a larger size (Experiment 1) and led individuals to judge subsequently presented neutral objects as larger in size (Experiment 2). In Experiment 3, similar effects were observed in a mock subliminal presentation paradigm. In Experiment 4, positive word primes were perceived to have been presented for a longer duration of time, again relative to both neutral and negative word primes. Results are discussed in relation to theories of approach motivation, affective priming, and the motivation-perception interface.     

Size contrast as a function of conceptual similarity between test and inducers

In four experiments, the effect of the semantic relationship between test and inducing stimuli on the magnitude of size contrast in an Ebbinghaus-type illusion was explored. In Experiments 1 and 2, the greatest illusion was found when test and inducing stimuli were identical in shape and differed only in size. Decreased size contrast was found when inducing stimuli were drawn from the same category as the test stimulus, but were not visually identical. Even less size contrast was found when inducing stimuli were from a near conceptual category, with the least effect when they were drawn from a completely different category. In Experiment 3, it was demonstrated that even if test and inducing stimuli are drawn with identical geometric elements, the size contrast illusion is greatly reduced if they represent apparently different conceptual categories (through the manipulation of orientation and perceptual set). In Experiment 4, any geometric or spatial confounds were ruled out. These results suggest that size contrast is strongly influenced by the conceptual similarity between test and inducing stimuli.     

A critical evaluation of visually moderated phonetic context effects

Fowler, Brown, and Mann (2000) have reported a visually moderated phonetic context effect in which a video disambiguates an acoustically ambiguous precursor syllable, which, in turn, influences perception of a subsequent syllable. In the present experiments, we explored this finding and the claims that stem from it. Experiment 1 failed to replicate Fowler et al. with novel materials modeled after the original study, but Experiment 2 successfully replicated the effect, using Fowler et al.'s stimulus materials. This discrepancy was investigated in Experiments 3 and 4, which demonstrate that variation in visual information concurrent with the test syllable is sufficient to account for the original results. Fowler et al.'s visually moderated phonetic context effect appears to have been a demonstration of audiovisual interaction between concurrent stimuli, and not an effect whereby preceding visual information elicits changes in the perception of subsequent speech sounds.     

The categorical structure of knowledge for famous people (and a novel application of Centre-Surround theory)

Knowledge of familiar people is essential to guide social interaction, yet there is uncertainty about whether semantic knowledge for people is stored in a categorical structure as for objects. Four priming experiments using hard-to-perceive primes investigated whether occupation forms a category connecting famous persons in semantic memory. Primes were famous faces exposed for 17ms with masking, resulting in severely restricted awareness and thus precluding expectancy-based priming effects. Targets were consciously perceptible famous faces (Experiments 1-3), famous names (Experiment 3), or occupations (Experiment 4) representing either the same or different occupation to the prime. Significant priming demonstrated the operation of automatic processes, including spreading activation, among persons sharing a common occupation; this supports the categorical view. The direction of priming (faster/slower responses to same-occupation than different-occupation targets) was dependent on prime-target stimulus onset asynchrony (Experiments 1-3) and type of target (Experiment 4). This pattern of results is attributed to the Centre-Surround mechanism proposed by Carr and Dagenbach [Carr, T. H., & Dagenbach, D. (1990). Semantic priming and repetition priming from masked words: evidence for a centre-surround attentional mechanism in perceptual recognition. Journal of Experimental Psychology: Learning, Memory and Cognition, 16, 341-350]. These results support (a) the categorical structure of semantic knowledge for famous people and (b) the application of the Centre-Surround mechanism to the domain of person recognition.     

The spatial mismatch effect is based on global configuration and not on perceptual records within the visual cache

If configurations of objects are presented in a S1-S2 matching task for the identity of objects a spatial mismatch effect occurs. Changing the (irrelevant) spatial layout lengthens response times. We investigated what causes this effect. We observed a reliable mismatch effect that was not influenced by a secondary task during maintenance. Neither articulatory suppression (Experiment 1), nor unattended (Experiments 2 and 6) or attended visual material (Experiment 3) reduced the effect, and this was independent of the length of the retention interval (Experiment 6). The effect was also rather independent of the visual appearance of the local elements. It was of similar size with color patches (Experiment 4) and with completely different surface information when testing was cross modal (Experiment 5), and the name-ability of the global configuration was not relevant (Experiments 6 and 7). In contrast, the figurative similarity of the configurations of S1 and S2 systematically influenced the size of the spatial mismatch effect (Experiment 7). We conclude that the spatial mismatch effect is caused by a mismatch of the global shape of the configuration stored together with the objects of S1 and not by a mismatch of templates of perceptual records maintained in a visual cache.