Presentation Of Comparison Stimuli Research Articles

Training Conditions for Establishing Visual Level 2 Perspective-Taking in Children with Autism Spectrum Disorder

Perspective transformations that are considered the first step of visual level 2 perspective-taking (VPT2) are not highly active in children with autism spectrum disorder (ASD). We investigated training procedures to develop moving to another viewpoint and observing the view from the new viewpoint to establish VPT2. The Face Rotation Task was used as the VPT2 task in three experiments. Experiments 1 and 2 examined the time-lag from the removal of sample stimuli to the presentation of comparison stimuli. The results of the two experiments indicated that VPT2 was established when participants move from the self-viewpoint to the other’s viewpoint while continuing to look at the stimuli, and when participants move from the other’s viewpoint to the self-viewpoint while maintaining a representation from the other’s viewpoint. Eye movements during the presentation of sample stimuli were analyzed in Experiment 3. The results indicated the possibility of mutually looking at elements of a spatial array while performing the perspective transformation.

Effects of Error-Contingent Prompts Depend on Temporal Arrangement of Stimuli in Symbolic Matching to Sample

In laboratory symbolic matching-to-sample (MTS) tasks, acquisition commonly proceeds via trial and error, whereas in applied settings, MTS instruction typically includes prompting and prompt-fading strategies. We examined the effects of error-contingent prompts in symbolic MTS under sample-first and comparison-first presentation arrangements. Three children (4–6 years) participated in each of two experiments. Each participant received two instructional sessions in each of four conditions, with new stimuli in each session. Dependent measures included terminal accuracy, items mastered, and overall efficiency across participants. In Experiment 1, error-contingent prompts facilitated acquisition under the comparison-first but not under the sample-first arrangement. In Experiment 2, the temporal arrangement of error correction trials was altered such that prompts did not delay the presentation of comparison stimuli. With this change, error-contingent prompts facilitated acquisition under both stimulus presentation arrangements. The results suggest that in a sample-first presentation format, prompts may be ineffective if they delay comparison presentation.

Short-term memory effects on visual global/local processing in tufted capuchin monkeys (Sapajus spp.).

Nonhuman primates, differently from humans, are less proficient at processing global properties of visual compound stimuli. It has been suggested that humans preferentially process stimuli globally because this enables a more economical encoding of the stimuli. In this study we assessed the role of short-term memory (STM) in global/local processing by presenting tufted capuchin monkeys with Navon-type hierarchical figures in both simultaneous and delayed matching-to-sample tasks. Capuchins' ability to discriminate hierarchical stimuli was evaluated as a function of increasing delay intervals (0.0, 0.5, 1.0, 2.0 and 3.0 sec) between the disappearance of the sample and the presentation of the comparison stimuli. The results showed that recognition accuracy for local features was above chance level with delays of up to 3.0 sec, as previously reported when capuchins were faced with nonhierarchical stimuli. By contrast, the recognition of global configurations was above chance level in simultaneous, 0.0 and 0.5 sec delay conditions but not at delay intervals of 1.0 sec or longer. These findings indicate that capuchins' propensity to process the local properties of visual stimuli can be observed when a delay is interposed between the presentation of sample and comparison stimuli and was not reversed by increasing the delay. Moreover, our results show that capuchins' local propensity was not reversed by increasing stimulus size. Overall, our study confirms crucial differences between human and nonhuman primates and adds new insights into the comparative research on visual grouping functions of these species. (PsycINFO Database Record

Context controls access to working and reference memory in the pigeon (Columba livia).

The interaction between working and reference memory systems was examined under conditions in which salient contextual cues were presented during memory retrieval. Ambient colored lights (red or green) bathed the operant chamber during the presentation of comparison stimuli in delayed matching-to-sample training (working memory) and during the presentation of the comparison stimuli as S+ and S- cues in discrimination training (reference memory). Strong competition between memory systems appeared when the same contextual cue appeared during working and reference memory training. When different contextual cues were used, however, working memory was completely protected from reference memory interference.

Identity matching in a patient with Alzheimer's disease.

Difficulties with short-term memory are one of the main problems in patients with dementia. Therefore, one purpose of this study was to examine the effects of simultaneous vs delayed presentation of comparison stimuli in a matching-to-sample (MTS) task using computerized training. By using an identity MTS procedure, the participant was trained to select a comparison stimulus identical to a sample stimulus. A 2nd purpose was to study the effect of the number of choices presented, thereby evaluating short-term memory deficits and possible deterioration of deficits over time. In this study, an 80-year-old-male with a Mini-Mental State Examination (MMSE) score of 10 was exposed to 4 experimental conditions. The results showed that using 3 comparison stimuli presented simultaneously with the sample stimulus on the screen resulted in more incorrect responding than when using 2 comparison stimuli. Furthermore, when adding a 0-second delay between the presentation of the sample stimulus and the 2 comparison stimuli, the number of correct responses did not exceed chance level.

Visual working memory of jungle crows (Corvus macrorhynchos) in operant delayed matching‐to‐sample1

AbstractWe examined the capacity of visual working memory in three male jungle crows using an operant delayed matching‐to‐sample procedure. In the delayed matching‐to‐sample, each trial started with the presentation of a sample stimulus, followed by the presentation of comparison stimuli after a delay interval. The choice of the matching comparison was rewarded. Jungle crows showed a steady decline in proportion correct with increasing delay interval. The proportion correct was higher when the sample stimulus was the same in the preceding trial, suggesting that proactive interference prevented the birds from retrieving the memory successfully. The analysis of response time revealed that response time was faster in correct than incorrect trials when the matching performance was acquired. Furthermore, response time linearly increased as the delay interval increased. Response time may reflect the processing of scanning memory as well as the level of confidence in their choice when retrieving.

REINFORCER CONTROL BY COMPARISON‐STIMULUS COLOR AND LOCATION IN A DELAYED MATCHING‐TO‐SAMPLE TASK

Six pigeons were trained in a delayed matching-to-sample task involving bright- and dim-yellow samples on a central key, a five-peck response requirement to either sample, a constant 1.5-s delay, and the presentation of comparison stimuli composed of red on the left key and green on the right key or vice versa. Green-key responses were occasionally reinforced following the dimmer-yellow sample, and red-key responses were occasionally reinforced following the brighter-yellow sample. Reinforcer delivery was controlled such that the distribution of reinforcers across both comparison-stimulus color and comparison-stimulus location could be varied systematically and independently across conditions. Matching accuracy was high throughout. The ratio of left to right side-key responses increased as the ratio of left to right reinforcers increased, the ratio of red to green responses increased as the ratio of red to green reinforcers increased, and there was no interaction between these variables. However, side-key biases were more sensitive to the distribution of reinforcers across key location than were comparison-color biases to the distribution of reinforcers across key color. An extension of Davison and Tustin's (1978) model of DMTS performance fit the data well, but the results were also consistent with an alternative theory of conditional discrimination performance (Jones, 2003) that calls for a conceptually distinct quantitative model.

RESISTANCE TO CHANGE OF FORGETTING FUNCTIONS AND RESPONSE RATES

This experiment examined the effects of reinforcement probability on resistance to change of remembering and response rate. Pigeons responded on a two-component multiple schedule in which completion of a variable-interval 20-s schedule produced delayed matching-to-sample trials in both components. Each session included four delays (0.1 s, 2 s, 4 s, and 8 s) between sample termination and presentation of comparison stimuli in both components. The two components differed in the probability of reinforcement arranged for correct matches (i.e., rich, p = .9; lean, p = .1). Response rates during the variable-interval portion of the procedure were higher in the rich component during baseline and more resistant to the disruptive effects of intercomponent food and extinction. Forgetting functions were constructed by examining matching accuracy as a function of delay duration. Baseline accuracy was higher in the rich component than in the lean component as measured by differences in the gamma-intercept of the forgetting functions (i.e., initial discrimination), rather than from differences in the slope of the forgetting function (i.e., rate of forgetting). Intercomponent food increased the rate of forgetting relatively more in the lean component than in the rich component, but initial discrimination was not systematically affected. Extinction reduced initial discrimination relatively more in the lean component than in the rich component, but did not systematically affect rate of forgetting. These results are consistent with our previous data suggesting that, as for response rate, accuracy and resistance to change of discriminating are positively related to rate of reinforcement. These data also suggest that the disruptability of remembering depends on the conditions of reinforcement, but the way in which remembering is disrupted depends on the nature of the disruptor.