Priming and stimulus-response learning in perceptual classification tasks

Participants often respond more quickly and more accurately to a repeated stimulus compared to a non-repeated one, a phenomenon known as repetition priming. In semantic classification tasks priming appears to be largely attributable to the learning of stimulus-decision and stimulus-response associations, which allow participants to bypass many of the processes engaged during initial stimulus analysis. The current study tested whether stimulus-response learning plays a similarly dominant role in priming that occurs in perceptual classification tasks. Unfamiliar objects were used as stimuli to reduce the influence of semantic processes on priming and the task switched for all test trials to eliminate stimulus-decision learning. The results showed across-task priming as measured by reaction time facilitation and improved accuracy when the response remained the same during the encoding and test phases. When the response switched, similar levels of reaction time facilitation were observed, but priming as measured by accuracy was significantly reduced and no longer significant. These findings indicate that stimulus-response learning contributes to priming in perceptual classification tasks, but does not play a dominant role. Significant stimulus-level learning that is independent of the task and response also occurs and likely indexes facilitated perceptual processing of the objects.     

Repetition advantage and disadvantage in perceptual identification tasks

Repetitive presentation of a stimulus brings not only advantage but also disadvantage when performing perceptual identification tasks. In this study, the conflicting phenomena of the effect of repetition were examined using two Kana character sets (Hiragana and Katakana) as stimuli. Two identical or different stimuli were presented in rapid succession and participants were asked to identify and report them. The stimulus onset asynchrony (SOA) between the two stimuli was varied from 200 ms to 1200 ms, according to which the suitable temporal conditions for the two distinct effects of repetition were explored. The results indicated that two distinct effects of repetition occurred depending on the informational code shared by the two stimuli. An interference effect of repetition was observed with SOA values of up to 500 ms when the two stimuli were identical in terms of their visual pattern code (Hiragana), whereas a superior effect of repetition was observed with an SOA value of 200 ms when they were identical only in terms of their phonological code (Hiragana and Katakana). From these findings, the author proposes that when two identical stimuli are presented in rapid succession, inhibition and activation mechanisms may function at different levels of processing.     

Generalization of relative competence mediating conformity across differing tasks

Subject correctness and group agreement were initially varied for college subjects performing a multiple-choice informational task (Canadian Knowledge Inventory). On a subsequent perceptual task (Raven's Standard Progressive Matrices), the dependent variable of conformity was assessed to examine generalization of relative competence formed on the informational task. It was seen that: (1) Those who perceived themselves to be less competent than the group on the first task exhibited the greatest level of conformity on the second task, thus replicating previous research on perceived relative competence as a determinant of conformity; (2) suspicion reduced conformity.     

Spatial processing and perceptual sequence learning in SRT tasks

We investigated the influence of processing relevant spatial information on learning a probabilistic sequence of irrelevant locations. Using the SRT design of Remillard (2003), we found that spatial perceptual learning occurs with paired but not with single targets. The pairs of targets consisted of the same stimuli, but in a different order, so that responses could have been based on the left-right location of an element, relative to the other element of the pair. The prerequisite of spatial pairs of targets suggests that spatial processing of relevant information plays a crucial role in perceptual location learning. In addition, spatial perceptual learning only took place when the target pair was presented together with other stimuli, but was absent when the target pair was presented in a blank field. Since in the latter case attention is automatically captured, this suggests that sequence learning requires endogenous attention.     

Rapid-response versus free-time selection tasks using different logical connectives

When reasoning with conditional statements (i.e., if [not] p then [not] q), people tend to display matching bias: Options that match the entities named in the rule are selected even when logically inappropriate. Three different Wason selection tasks were administered under free-time and rapid-response formats. For the latter, individual cards were presented for one second, and required a response within a further one second. Previous research using these formats (Roberts & Newton, 2001) has shown that this increases matching bias, in line with the action of preconscious heuristic processes which direct attention towards relevant aspects of a problem, but whose action can be overturned if there is sufficient time to apply analytic reasoning processes. The selection tasks administered included a standard abstract conditional task, a disjunctive version (i.e., either [not] p or [not] q), and a conditional task in which the cards showed explicitly negated values. Both conditional tasks demonstrated matching bias, but under rapid-response presentation, matching bias only increased for the standard conditional and disjunctive tasks. Overall, the data support Evans’ (e.g., 2006) heuristic-analytic framework albeit with some caveats, and it is suggested that the broad question, of whether individual selection task formats show or do not show matching bias, requires more detailed investigation.     

Technique for estimating perceptual noise in categorization tasks

A procedure, based on the method of adjustment, for estimating perceptual noise is presented. The resulting estimates can be used to obtain a better understanding of categorization behavior, to answer questions about the distributional form of perceptual noise, and to test for perceptual independence. All three applications are demonstrated in a categorization task involving two categories.     

Competition between memory and perceptual tasks involving physically similar stimuli

Performance on a perceptual recognition task and a concurrently performed short-term memory (STM) task was studied. The stimuli used in the STM task were either visually similar, acoustically similar, or dissimilar to the stimuli in the perceptual task. The results demonstrated that any type of concurrent list memorization has a detrimental effect upon perceptual performance, but this effect is magnified if the stimuli used in the 2 tasks are visually similar. Acoustic similarity had no effect. The results document the fact that distinct tasks interfere, when the tasks compete for a limited total processing capacity, or when the tasks demand the same visual coding program.     

On the generality of logical recoding in spatial interference tasks

‘Simon’ and ‘recoding’ affects refer to interference by irrelevant spatial stimulus positions on the efficiency of responding to a stimulus. According to the Simon effect faster response times occur if the irrelevant stimulus position is compatible with the response position. Slower response times occur if stimulus and response positions are incompatible. The recoding effect is a reversed Simon effect, which occurs if the response assignment of the relevant stimuli is reversed, e.g., a red response button to a green stimulus and a green response button to a red stimulus. For this reversed response assignment response times are faster if stimulus and response positions are incompatible, and slower if stimulus and response positions are compatible. In this study the generality of the recoding effect in spatial interference tasks is investigated by using, first, spatial stimuli with directional attributes, second, verbal stimuli with a directional meaning, and, third, geometric figures without directional information. In all cases Simon effects as well as recoding effects were obtained. According to these results recoding does not presuppose a directional symbolic or verbal stimulus code, and the relation between the stimulus and the spatial response may be either direct, symbolic or arbitrary. Whether recoding or a Simon effect will occur depends on a late response decision stage in which the response code derived from the stimulus is either inverted (recoding effect) or not (Simon effect).     

The perceptual wink model of non-switching attentional blink tasks

The attentional blink (AB) is a temporary deficit for a second target (T2) when that target appears after a first target (T1). Although sophisticated models have been developed to explain the substantial AB literature in isolation, the current study considers how the AB relates to perceptual dynamics more broadly. We show that the time-course of the AB is closely related to the time course of the transition from positive to negative repetition priming effects in perceptual identification. Many AB tasks involve a switch between a T1 defined in one manner and a T2 defined in a different manner. Other AB tasks are non-switching, with all targets belonging to the same well-known category (e.g., letter targets versus number distractors) or sharing the same perceptual feature. We propose that these non-switching AB tasks reflect perceptual habituation for the target-defining attribute; thus, a ‘perceptual wink’, with perception of one attribute (target identity) undisturbed while perception of another (target detection) is impaired. On this account, the immediate benefit following T1 (lag-1 sparing) reflects positive repetition priming and the subsequent deficit (the blink) reflects negative repetition priming for the realization that a target occurred. In developing the perceptual wink model, we extended the nROUSE model of perceptual priming to explain the results of two new experiments combining the AB and identity repetitions. This establishes important connections between non-switching AB tasks and perceptual dynamics.     

Transient sex differences during adolescence on auditory perceptual tasks

Many perceptual abilities differ between the sexes. Because these sex differences have been documented almost exclusively in adults, they have been attributed to sex‐specific neural circuitry that emerges during development and is maintained in the mature perceptual system. To investigate whether behavioral sex differences in perception can also have other origins, we compared performance between males and females ranging in age from 8 to 30 years on auditory temporal‐interval discrimination and tone‐in‐noise detection tasks on which there are no sex differences in adults. If sex differences in perception arise only from the establishment and subsequent maintenance of sex‐specific neural circuitry, there should be no sex differences during development on these tasks. In contrast, sex differences emerged in adolescence but resolved by adulthood on two of the six conditions, with signs of a similar pattern on a third condition. In each case, males reached mature performance earlier than females, resulting in a sex difference in the interim. These results suggest that sex differences in perception may arise from differences in the maturational timing of common circuitry used by both sexes. They also imply that sex differences in perceptual abilities may be more prevalent than previously thought based on adult data alone.     

An investigation of false memory in perceptual implicit tasks

Reports of critical lure priming in perceptual implicit tasks [e.g., McKone, E., & Murphy, B. (2000). Implicit false memory: Effects of modality and multiple study presentations on long-lived semantic priming. Journal of Memory and Language, 43, 89-109] using the Deese-Roediger-McDermott [Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803-814] procedure have suggested availability of the lexical form of lure items at study. Three experiments were conducted to further explore "false" implicit priming in perceptual tests. In Experiments 1 and 3, implicit and explicit stem completion tests were given in the DRM procedure with semantic lists; in Experiment 2, a graphemic response test was used in a similar design. For all experiments, explicit instructions resulted in reliable false memory, while implicit instructions resulted in priming for list items and no priming for lure items. Priming for lure items was evident for "test-aware" subjects only in Experiment 1 and in a combined analysis for all three experiments. These results establish boundary conditions for priming for critical lures and indicate that access to the lexical form of critical lures may not occur under incidental learning conditions when strong controls against explicit retrieval are implemented.     

Locus of control and effects of perceptual tasks on heart rate

The hypothesis was tested that the relationship found in prior research between heart rate changes produced in biofeedback settings and locus of control scores derives from the heart-brain relationship described by the Laceys in 1967, as well as from "expectancies for control." 48 subjects were tested on two perceptual tasks known to elicit changes in heart rate. Significant heart rate changes were observed in response to both tasks, but those changes did not correlate with locus of control as measured by scores on the Rotter I-E Scale and the Multidimensional Health Locus of Control Scale. Explanations for these results are offered.     

Working memory does not dissociate between different perceptual categorization tasks

Working memory is crucial for many higher level cognitive functions, ranging from mental arithmetic to reasoning and problem solving. Likewise, the ability to learn and categorize novel concepts forms an indispensable part of human cognition. However, very little is known about the relationship between working memory and categorization. This article reports 2 studies that related people's working memory capacity (WMC) to their learning performance on multiple rule-based and information-integration perceptual categorization tasks. In both studies, structural equation modeling revealed a strong relationship between WMC and category learning irrespective of the requirement to integrate information across multiple perceptual dimensions. WMC was also uniformly related to people's ability to focus on the most task-appropriate strategy, regardless of whether or not that strategy involved information integration. Contrary to the predictions of the multiple systems view of categorization, working memory thus appears to underpin performance in both major classes of perceptual category-learning tasks.     

Relating inter-individual differences in metacognitive performance on different perceptual tasks

Human behavior depends on the ability to effectively introspect about our performance. For simple perceptual decisions, this introspective or metacognitive ability varies substantially across individuals and is correlated with the structure of focal areas in prefrontal cortex. This raises the possibility that the ability to introspect about different perceptual decisions might be mediated by a common cognitive process. To test this hypothesis, we examined whether inter-individual differences in metacognitive ability were correlated across two different perceptual tasks where individuals made judgments about different and unrelated visual stimulus properties. We found that inter-individual differences were strongly correlated between the two tasks for metacognitive ability but not objective performance. Such stability of an individual’s metacognitive ability across different perceptual tasks indicates a general mechanism supporting metacognition independent of the specific task.     

Internalization versus compliance: Differential processes underlying minority influence and conformity

Two experiments investigated whether minority influence and conformity operate by the same or by different processes. It was predicted that subjects who were simultaneously exposed to a majority and a minority opinion would move towards the minority in private but towards the majority in public. The results of Experiment 1 supported this hypothesis. Experiment 2 investigated three hypotheses predicting that (1) the above interaction would be replicated, (2) minorities would trigger more arguments and counter-arguments, and (3) cognitive activity would mediate internalization but not compliance. Hypotheses 1 and 3 were supported. The second hypothesis was not supported. However, minorities were found to trigger more arguments and fewer counter-arguments than majorities. The results were interpreted as supporting the dual process model.