Binocular rivalry: a window into emotional processing in aging

Previous binocular rivalry studies with younger adults have shown that emotional stimuli dominate perception over neutral stimuli. Here we investigated the effects of age on patterns of emotional dominance during binocular rivalry. Participants performed a face/house rivalry task where the emotion of the face (happy, angry, neutral) and orientation (upright, inverted) of the face and house stimuli were varied systematically. Age differences were found with younger adults showing a general emotionality effect (happy and angry faces were more dominant than neutral faces) and older adults showing inhibition of anger (neutral faces were more dominant than angry faces) and positivity effects (happy faces were more dominant than both angry and neutral faces). Age differences in dominance patterns were reflected by slower rivalry rates for both happy and angry compared to neutral face/house pairs in younger adults, and slower rivalry rates for happy compared to both angry and neutral face/house pairs in older adults. Importantly, these patterns of emotional dominance and slower rivalry rates for emotional-face/house pairs disappeared when the stimuli were inverted. This suggests that emotional valence, and not low-level image features, were responsible for the emotional bias in both age groups. Given that binocular rivalry has a limited role for voluntary control, the findings imply that anger suppression and positivity effects in older adults may extend to more automatic tasks.     

Transformation of visual neural signals into psychological information

A theory is proposed which transforms visual neural signals into the psychological information and which explains visual illusions. As an example, Poggendorff's illusion is explained.     

Speed-accuracy decomposition yields a sudden insight into all-or-none information processing

The existence of discrete all-or-none information processing has often been assumed as a basis for stage models and also as an important characteristic of nonlinear connectionist models; however, there has been little or no hard empirical evidence supporting the existence of this phenomenon. In search of such evidence, we applied speed-accuracy decomposition (Meyer et al., 1988), a technique for detecting partial response information, to the examination of the time-course of processing in a (Gestalt) insight-like task, namely, anagram solution. This task was chosen because the Gestalt psychologists conjectured that insight is a sudden, discrete phenomenon. Supporting this view, we found little or no evidence of partial information in two experiments, thereby providing what may be the strongest evidence to date for all-or-none processing.     

Novelty and processing demands in conceptual combination

In this article, we sought to isolate the processing demands of combining the concepts of modifier‐noun phrases from those of other language comprehension processes. Probe reaction time (RT) was used as an indication of the processing resources required for combining concepts. Phrase frequency (as measured by Google hit rates) was used as a metric of the degree of conceptual combination required for each phrase. Participants were asked to interpret modifier‐noun phrases using a sense‐nonsense decision (Experiment 1) and a phrase meaning access task (Experiment 2). Experiment 2 also used a lexical decision task to activate the word's individual meanings. Regression analyses for both experiments indicated that phrase frequency (indicating novelty) predicts a significant portion of the probe RT variance, such that low‐frequency phrases required more processing resources than high‐frequency phrases, when controlling for associative strength, word frequency, letter length, and lexical‐semantic activation. Overall, this study indicates that conceptual combination requires processing resources beyond those of other language processes.     

Binocular processing of brightness information: a vector-sum model

The relation between monocular and binocular brightness was examined. Clear evidence was found that the interaction between visual channels in binocular processing of brightness information implicates both an apparent averaging of monocular brightness when they are grossly different and a partial summation when they approach equality. A vector-sum model is shown to predict these properties. A nonmetric method was used to fit such a model to data from three experiments in each of which 15 subjects estimated brightness of binocularly fused targets. Magnitude estimation was used in two experiments, and cateogry ratings were obtained in the third experiment. When it was assumed only that subjects' responses were monotone with perceived brightness, estimates of the model's parameters from the data of the three experiments were almost identical, indicating that results from magnitude estimati;n and category rating can converge once nonlinear response functions are eliminated.     

Temporal expectation and information processing: a model-based analysis

People are able to use temporal cues to anticipate the timing of an event, enabling them to process that event more efficiently. We conducted two experiments, using the fixed-foreperiod paradigm (Experiment 1) and the temporal-cueing paradigm (Experiment 2), to assess which components of information processing are speeded when subjects use such temporal cues to predict the onset of a target stimulus. We analyzed the observed temporal expectation effects on task performance using sequential-sampling models of decision making: the Ratcliff diffusion model and the shifted-Wald model. The results from the two experiments were consistent: temporal expectation affected the duration of nondecision processes (target encoding and/or response preparation) but had little effect on the two main components of the decision process: response-threshold setting and the rate of evidence accumulation. Our findings provide novel evidence about the psychological processes underlying temporal-expectation effects on reaction time.     

Gestalt and feature-intensive processing: Toward a unified model of human information processing

“Cognitive asynchrony theory,” recently developed in research on aging and memory, implies a functional distinction between the processing of “feature-intensive” items, those with numerous identifiable features, and the processing of images which are relatively sparse in such features and are handled in a more wholistic, “gestalt” manner. The present experiments addressed the question of whether such a distinction exists outside the realms of memory in which it has thus far been addressed. The present work used mental rotation as a model system. Consistent with the predictions of this model, Experiment 1 showed that feature-intensive figures required significantly more time to rotate than did gestalt figures, even though angles of rotation were the same. Experiment 2 demonstrated that feature-intensive processing may involve verbally-accessible semantic systems to a greater degree than is the case with “gestalt” items. Experiment 3 identified significant practice effects of feature-intensive stimuli on the processing of gestalt stimuli, but not the reverse. The results of these experiments indicate that the “gestalt/feature-intensive” processing distinction extends to mental rotation as well as to memory. Implications for the nature of mental representation of verbal and visual materials are discussed.     

Gestalt and feature-intensive processing: Toward a unified model of human information processing

“Cognitive asynchrony theory,” recently developed in research on aging and memory, implies a functional distinction between the processing of “feature-intensive” items, those with numerous identifiable features, and the processing of images which are relatively sparse in such features and are handled in a more wholistic, “gestalt” manner. The present experiments addressed the question of whether such a distinction exists outside the realms of memory in which it has thus far been addressed. The present work used mental rotation as a model system. Consistent with the predictions of this model, Experiment 1 showed that feature-intensive figures required significantly more time to rotate than did gestalt figures, even though angles of rotation were the same. Experiment 2 demonstrated that feature-intensive processing may involve verbally-accessible semantic systems to a greater degree than is the case with “gestalt” items. Experiment 3 identified significant practice effects of feature-intensive stimuli on the processing of gestalt stimuli, but not the reverse. The results of these experiments indicate that the “gestalt/feature-intensive” processing distinction extends to mental rotation as well as to memory. Implications for the nature of mental representation of verbal and visual materials are discussed.     

The Slip Induction Task: Creating a window into cognitive control failures

Regardless of age, education, or social status, we all experience moments where we ask ourselves, "what was I thinking?!?" Typically, we experience errors of this sort, or slips of action, during routine tasks that require a whole sequence of movements. However, most action slip research has focused on creating response conflict within single movements. The Slip Induction Task (SIT) is a step toward creating response conflict within truer to life action routines. As such, the SIT attempts to induce action slips in a well-learned movement routine through the occasional presentation of unexpected cues. We find that the SIT is able to reliably induce action slips, especially when the unexpected cue necessitates a movement to an unexpected target location. Furthermore, when participants are able to avoid an action slip, these changes in movement routine are accompanied by a cost in speed.     

Spatial information processing consequences of DAMGO injections into the dorsal striatum

The purpose of the present study was to examine the role of the dorsal striatum, and more specifically, the patch region of the dorsal striatum, in mediating spatial learning and memory. To this end, male, Long Evans rats were bilaterally implanted with cannula aimed at the dorsal striatum. Rats were injected with different doses (0, 0.05, 0.5 or 5 microg/0.5 microl) of [3H]-[D-Ala2,MePhe4,Gly-ol5]-enkephalin (DAMGO) into the dorsal striatum daily (Exp. 1) before training on a hidden platform version of the water maze task or during a reversal water maze spatial task (Exp. 2). In both experiments, probe retention tests were given drug free. Results from Exp. 1 showed that intra-striatal injection of the low DAMGO dose (0.05) resulted in enhanced spatial acquisition while the high dose (5.0) produced impairments compared to controls. During the probe test, the low dose group showed better retention of the platform location than controls as well as an enhanced ability to alter their search strategy. In Exp. 2, pretraining alleviated the high dose impairment found in Exp. 1 suggesting a motoric impairment in this group. The low dose group continued to show an enhanced ability to alter their search strategy during the probe test compared to all other groups. The data suggest that the low dose of DAMGO, when injected into the dorsal striatum, eliminates competition with the hippocampus thereby leading to enhanced spatial processing. Alternatively, inhibition of patch-striatal neurons may attenuate a memory decay process. Both alternatives are discussed.     

Sequential effects on speeded information processing: a developmental study

Two experiments were performed to assess age-related changes in sequential effects on choice reaction time (RT). Sequential effects portray the influence of previous trials on the RT to the current stimulus. In Experiment 1, three age groups (7-9, 10-12, and 18-25 years) performed a spatially compatible choice task, with response-to-stimulus intervals (RSIs) of 50 and 500 ms varied between trial blocks. In Experiment 2, three age groups (7-9, 15-16, and 18-25 years) performed the task with spatial stimulus-response (S-R) mappings (compatible versus incompatible) varied between participants. For adults, the experiments yielded a pattern of sequential effects suggestive of "automatic facilitation" (i.e., a first-order repetition effect and a higher order benefit-only pattern for short RSIs) and "subjective expectancy" (i.e., a first-order alternation effect and a higher order cost-benefit pattern for long RSIs). Automatic facilitation was more pronounced for incompatible responses than for compatible responses. Both experiments showed the anticipated decrease in automatic facilitation with advancing age. Finally, the first-order alternation effect showed the predicted age-related increase, but the cost-benefit pattern revealed an opposite trend, suggesting that the first-order and higher order indexes of subjective expectancy may relate to dissociable mechanisms.     

State-dependent processing of serial signals

The relation between EEG patterns and performance, which was found experimentally, gives evidence for a state dependent information processing. The power distribution of the EEG one second before the stimulus onset determines the state measured by the used data acquisition system. To solve the on-line identification of the state four different approaches are proposed and compared. The two modes of triggering the stimulus onset labeled by alpha wave state and non alpha wave state led to significantly different reaction times. The proposed stochastic recurrence equation can be used to model the scanning process performed by 17 subjects in solving the task of searching the first number in a string of characters. The model is based on the decomposition of the measured reaction times according to the assumed elementary processes.     

Chromatic information processing

The investigation of visual processing mediated solely by chromatic information requires conditions preventing a subject's use of the luminance differences normally accompanying a chromatic change. In Experiment 1, which involved a discriminative reaction time (RT) task, chromatic and white stimuli of the same luminance were presented on a dimmer achromatic background. Subjects were instructed to respond only to the chromatic stimuli. RT was slowest at 570 nm and somewhat faster to short wavelengths than to long wavelengths. In Experiment 2, which compared two discriminative RT tasks, RT was faster when subjects responded to color than when they responded to white. Experiments 3 and 4 demonstrated that a brighter white surround decreased the perceived brightness of chromatic stimuli as well as their perceptual similarity to white, but did not affect RT. The results are discussed in terms of the response strength of the chromatic processing channel.     

Selective information processing

Past studies have shown that in certain tasks, subjects are not able to selectively attend to specific areas of a visual display even if instructed to do so. Yet, a more recent study (Graves, 1976) has used the concept of selective attention to explain the difference between the number of items processed in forced choice detection tasks and the number processed in full report tasks. Graves proposed that only identification processing is necessary in the detection task, while both identification and position processing are required in the full report task. A problem with Graves’ task is that it requires memory searching after stimulus presentation, probably reducing the predicted number of items processed. The experiment reported here utilized partially filled arrays and required responses based upon only positional processing, or only identification processing, or both types of processing. In direct contradiction to Graves’ conclusions, the results showed that although subjects could inhibit identification processing while engaged in positional processing, the reverse was not true. In addition, positional processing was shown to be faster than identification processing.