Eurasian jays (Garrulus glandarius) conceal caches from onlookers

Animals that cache food risk having their stored food pilfered by conspecifics. Previous research has shown that a number of food-caching species of corvid use strategies that decrease the probability of conspecifics pilfering their caches. In this experiment, we investigated whether Eurasian jays (Garrulus glandarius) would choose between caching behind an opaque and caching behind a transparent barrier whilst being observed by a conspecific. If caching in out-of-sight locations is a strategy to prevent conspecifics from pilfering these caches, then the jays should place a greater proportion of caches behind the opaque barrier when being observed than when caching in private. In accordance with this prediction, jays cached a greater proportion of food behind the opaque barrier when they were observed than when they cached in private. These results suggest that Eurasian jays may opt to cache in out-of-view locations to reduce the likelihood of conspecifics pilfering their caches.     

Development of the ability to combine visual and acoustic information in working memory

Presentation of two kinds of materials in working memory (visual and acoustic), with the requirement to attend to one or both modalities, poses an interesting case for working memory development because competing predictions can be formulated. In two experiments, we assessed such predictions with children 7–13 years old and adults. With development, the ability to hold more information in the focus of attention could lead to an increase in the size of the trade‐off between modalities; if attention can hold A items during unimodal‐attention trials, then on average attention should hold A/2 of those same items during bimodal‐attention trials. If A increases with age, so would the dual‐task cost, A/2. The results clearly ruled out that possibility. It was the modality‐ or code‐specific components of working memory that improved with age and not the central component. We discuss various mechanisms that could have produced these results, including alternative attention‐based mechanisms. The findings point to a rich field for continued research.     

Magpies can use local cues to retrieve their food caches

Much importance has been placed on the use of spatial cues by food-hoarding birds in the retrieval of their caches. In this study, we investigate whether food-hoarding birds can be trained to use local cues (“beacons”) in their cache retrieval. We test magpies (Pica pica) in an active hoarding-retrieval paradigm, where local cues are always reliable, while spatial cues are not. Our results show that the birds use the local cues to retrieve their caches, even when occasionally contradicting spatial information is available. The design of our study does not allow us to test rigorously whether the birds prefer using local over spatial cues, nor to investigate the process through which they learn to use local cues. We furthermore provide evidence that magpies develop landmark preferences, which improve their retrieval accuracy. Our findings support the hypothesis that birds are flexible in their use of memory information, using a combination of the most reliable or salient information to retrieve their caches.     

Young infants readily use proximity to organize visual pattern information

Four experiments relying on novelty and spontaneous preference procedures were performed to determine whether 3-4-month-old infants utilize the Gestalt principle of proximity to organize visual pattern information. In Experiment 1, infants familiarized with arrays of elements that could be organized into either columns or rows were tested for their preference between vertical and horizontal bars. The infants preferred the novel organization of bars. Experiments 2 and 3 showed that the novelty preference could not be attributed to an a priori preference or an inability to discriminate between the elements comprising the patterns. Experiment 4 replicated the results of Experiment 1 in a bars --> elements version of the task, indicating that extended exposure is not necessary for infants to organize based on proximity. The results suggest that infants readily organize visual pattern information in accord with proximity. Implications of this finding for models of the ontogenesis and microgenesis of object perception in infants and adults are discussed.     

The use of visual information in natural scenes

Despite the complexity and diversity of natural scenes, humans are very fast and accurate at identifying basic-level scene categories. In this paper we develop a new technique (based on Bubbles, Gosselin & Schyns, 2001a; Schyns, Bonnar, & Gosselin, 2002) to determine some of the information requirements of basic-level scene categorizations. Using 2400 scenes from an established scene database (Oliva & Torralba, 2001), the algorithm randomly samples the Fourier coefficients of the phase spectrum. Sampled Fourier coefficients retain their original phase while the phase of nonsampled coefficients is replaced with that of white noise. Observers categorized the stimuli into 8 basic-level categories. The location of the sampled Fourier coefficients leading to correct categorizations was recorded per trial. Statistical analyses revealed the major scales and orientations of the phase spectrum that observers used to distinguish scene categories.     

Scrub jays (Aphelocoma coerulescens) remember the relative time of caching as well as the location and content of their caches

Two experiments examined whether food-storing scrub jays (Aphelocoma coerulescens) could remember when they cached particular food items as well as what they cached and where. In Experiment 1, scrub jays cached and recovered perishable "wax worms" (wax moth larvae) and nonperishable peanuts in 2 visuospatially distinct and trial-unique trays. The birds searched preferentially for fresh wax worms if they had cached them 4 hr earlier but rapidly learned to search for peanuts and avoid decayed wax worms that had been cached 124 hr previously. This pattern also was observed when the food items were removed before recovery on test trials. These results were replicated in Experiment 2 using a procedure in which both types of food were cached in different sides of the same caching tray: On the basis of a single, trial-unique experience, scrub jays could remember the relative time of caching as well as what type of food was cached in each cache site.     

Covert visual attention and extrafoveal information use during object identification

Three experiments are reported that examined the relationship between covert visual attention and a viewer's ability to use extrafoveal visual information during object identification. Subjects looked at arrays of four objects while their eye movements were recorded. Their task was to identify the objects in the array for an immediate probe memory test. During viewing, the number and location of objects visible during given fixations were manipulated. In Experiments 1 and 2, we found that multiple extrafoveal previews of an object did not afford any more benefit than a single extrafoveal preview, as assessed by means of time of fixation on the objects. In Experiment 3, we found evidence for a model in which extrafoveal information acquired during a fixation derives primarily from the location toward which the eyes will move next. The results are discussed in terms of their implications for the relationship between covert visual attention and extrafoveal information use, and a sequential attention model is proposed.     

Alignment to visual speech information

Speech alignment is the tendency for interlocutors to unconsciously imitate one another’s speaking style. Alignment also occurs when a talker is asked to shadow recorded words (e.g., Shockley, Sabadini, & Fowler, 2004). In two experiments, we examined whether alignment could be induced with visual (lipread) speech and with auditory speech. In Experiment 1, we asked subjects to lipread and shadow out loud a model silently uttering words. The results indicate that shadowed utterances sounded more similar to the model’s utterances than did subjects’ nonshadowed read utterances. This suggests that speech alignment can be based on visual speech. In Experiment 2, we tested whether raters could perceive alignment across modalities. Raters were asked to judge the relative similarity between a model’s visual (silent video) utterance and subjects’ audio utterances. The subjects’ shadowed utterances were again judged as more similar to the model’s than were read utterances, suggesting that raters are sensitive to cross-modal similarity between aligned words.     

Insensitivity of visual short-term memory to irrelevant visual information

Several authors have hypothesized that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996b). Experiment 1 replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of DVN on recall of static matrix patterns, despite a significant effect of a concurrent spatial tapping task. Experiment 4 showed no effect of DVN on encoding or maintenance of arrays of matrix patterns, despite testing memory by a recognition procedure to encourage visual rather than spatial processing. Serial position curves showed a one-item recency effect typical of visual short-term memory. Experiment 5 showed no effect of DVN on short-term recognition of Chinese characters, despite effects of visual similarity and a concurrent colour memory task that confirmed visual processing of the characters. We conclude that irrelevant visual noise does not impair visual short-term memory. Visual working memory may not be functionally analogous to verbal working memory, and different cognitive processes may underlie visual short-term memory and visual imagery.     

Human sensitivity to acoustic information from vessel filling

A cylindrical vessel's fundamental resonant frequency increases as it fills with water. In Experiment 1, observers reliably identified water level rising, falling, or not changing. In Experiment 2, observers controlled filling well using only auditory information but less well than with multimodal information. Observers controlled fills to the brim better than to a drinking level, implying anticipation of fullness. In Experiment 3, blind and blindfolded sighted observers filled vessels to the brim using only auditory information. Fills tracked vessel height and flow rate well (R = .93, blind; R = .86, sighted). Experiment 4 tested sensitivity to acoustic time-to-full (TTF), analogous to optical tau. Estimated TTF to 3 fill levels at 3 rates tracked actual TTF (group R > .9; individual median R = .82). Results supported ecological perceptual theory: Changing acoustic information affords adaptive, prospective control of vessel filling.     

Additivity, subadditivity, and the use of visual information: a reply to Massaro (1988)

Previously we (Bruno & Cutting, 1988) explored the perception of spatial relations among objects laid out in a computer-generated environment. In his commentary on our article, Massaro (1988) raised several issues. The most important is from his reanalysis, which indicated that--because of a subadditive trend in the results--additive and multiplicative strategies fit our data in Experiment 1 about equally well. In reply, we performed a different analysis. Results corroborate subadditivity--and hence multiplicative information combination--in Experiment 1 but provide no evidence for it in Experiments 2 and 3. On the whole, then, the results still support additivity more strongly than any other combination rule and thus support our notion of minimodularity.     

Domestic dogs (Canis familiaris) use a physical marker to locate hidden food

Dogs can use the placement of an arbitrary marker to locate hidden food in an object-choice situation. We tested domestic dogs (Canis familiaris) in three studies aimed at pinning down the relative contributions of the human’s hand and the marker itself. We baited one of two cups (outside of the dogs’ view) and gave the dog a communicative cue to find the food. Study 1 systematically varied dogs’ perceptual access to the marker placing event, so that dogs saw either the whole human, the hand only, the marker only, or nothing. Follow-up trials investigated the effect of removing the marker before the dog’s choice. Dogs used the marker as a communicative cue even when it had been removed prior to the dog’s choice and attached more importance to this cue than to the hand that placed it although the presence of the hand boosted performance when it appeared together with the marker. Study 2 directly contrasted the importance of the hand and the marker and revealed that the effect of the marker diminished if it had been associated with both cups. In contrast touching both cups with the hand had no effect on performance. Study 3 investigated whether the means of marker placement (intentional or accidental) had an effect on dogs’ choices. Results showed that dogs did not differentiate intentional and accidental placing of the marker. These results suggest that dogs use the marker as a genuine communicative cue quite independently from the experimenter’s actions.     

Spectral information for detection of acoustic time to arrival

The exponential increase of intensity for an approaching sound source provides salient information for a listener to make judgments of time to arrival (TTA). Specifically, a listener will experience a greater rate of increasing intensity for higher than for lower frequencies during a sound source’s approach. To examine the relative importance of this spectral information, listeners were asked to make judgments about the arrival times of nine 1-octave-band sound sources (the bands were consecutive, nonoverlapping single octaves, ranging from 40–80 Hz to ~10–20 kHz). As is typical in TTA tasks, listeners tended to underestimate the arrival time of the approaching sound source. In naturally occurring and independently manipulated amplification curves, bands with center frequencies between 120 and 250 Hz caused the least underestimation, and bands with center frequencies between 2000 and 7500 Hz caused the most underestimation. This spectral influence appears to be related to the greater perceived urgency of higher-frequency sounds.     

The sound of motion in spoken language: visual information conveyed by acoustic properties of speech

Language is generally viewed as conveying information through symbols whose form is arbitrarily related to their meaning. This arbitrary relation is often assumed to also characterize the mental representations underlying language comprehension. We explore the idea that visuo-spatial information can be analogically conveyed through acoustic properties of speech and that such information is integrated into an analog perceptual representation as a natural part of comprehension. Listeners heard sentences describing objects, spoken at varying speaking rates. After each sentence, participants saw a picture of an object and judged whether it had been mentioned in the sentence. Participants were faster to recognize the object when motion implied by speaking rate matched the motion implied by the picture. Results suggest that visuo-spatial referential information can be analogically conveyed and represented.     

The infant's use of visual and haptic information in the perception and recognition of objects

The purpose of this paper is to discuss the relationship between the haptic and visual systems during infant's bimodal interaction with objects. Four general topics are discussed: the role of exploratory activity in perception, the specific ways in which the two systems are related during exploration, developments over age in the relationship between the systems, and the impact of the organism/environment relationship on these developments.     

Visual and acoustic confusability a visual search task

Visual and acoustic confusability between a target item and background items was varied in a visual search task. Visual confusability was a highly significant source of difficulty while acoustic confusability had no effect. The results do not seem to be interpretable within a theory which assumes compulsory auditory encoding of visual information.     

Visual and acoustic confusability a visual search task

Visual and acoustic confusability between a target item and background items was varied in a visual search task. Visual confusability was a highly significant source of difficulty while acoustic confusability had no effect. The results do not seem to be interpretable within a theory which assumes compulsory auditory encoding of visual information.     

Show me the features! Understanding recognition from the use of visual information

We propose an approach that allows a rigorous understanding of the visual categorization and recognition process without asking direct questions about unobservable memory representations. Our approach builds on the selective use of visual information in recognition and a new method (Bubbles) to depict and measure what this information is. We examine three face–recognition tasks (identity, gender, expressive or not) and establish the componential and holistic information responsible for recognition performance. On the basis of this information, we derive task–specific gradients of probability for the allocation of attention to the different regions of the face.     

The use of time and trajectory forms as visual information about spatial scale in events

Spatial metrics are lost but temporal metrics are preserved in the mapping from events to optic flow. In marumate events governed by gravity, temporal scale is linked to spatial scale in ways specific to particular events. We tested whether time can be used as information about spatial scale in visually recognizable events. On average, observers were able to judge object size in event displays that eliminated information other than time and trajectory forms. However, judgment variability was substantial. After feedback on one event, observers judging distance performed better and generalized training to other events. Observers are sensitive to the general form of the scaling relation, but they require feedback to attune event-specific constants.     

Retinal painting and visual information storage

As a measure of visual information storage (VIS), Haber and Nathanson (1968) have used a retinal painting task involving passing a narrow slit across a drawing which the S has to see as a single percept. Two experiments were conducted to evaluate this task as a measure of VIS. In experiment 1 it was shown that contrary to other measures of VIS, adults have longer values than children. In experiment 2 dyslexic and control children performed at equivalent levels on this task. It is suggested that retinal painting involves a different persistence effect to that normally used as a measure of VIS.