Persistence and accommodation in short‐term priming and other perceptual paradigms: temporal segregation through synaptic depression

Perceptual input changes constantly in an unpredictable fashion, often changing before our somewhat sluggish perceptual systems have adequately processed this input. This can give rise to source confusion—how do we know whether a given perceptual activation is due to the current input, or a previous input that had yet to be completely processed? We propose that activity‐dependent neural accommodation naturally limits this source confusion by suppressing items once they have been identified. We review behavioral paradigms from different literatures that measure the correlates of persistence and accommodation. Of the various accommodative mechanisms, we focus on synaptic depression, deriving a rate‐coded expression that can be used to produce accommodating dynamics in any neural network with real valued activation. We implement this expression in a hierarchical model of perception termed, “a neural mechanism for responding optimally with unknown sources of evidence” (nROUSE). This model can be viewed as a more detailed version of the more abstract ROUSE model of Huber, Shiffrin, Lyle, and Ruys (2001), which produces accommodated levels of feature evidence through an optimal calculation. We apply nROUSE to three short‐term priming experiments that manipulated prime duration.     

Categorizing identity from facial motion

It has been suggested that acronyms like BBC are processed like real words. This claim has been based on improved performance with acronyms in the Reicher–Wheeler task, the letter string matching task, the visual feature integration task, and the N400 component in event-related potential (ERP) studies. Unfortunately, in all these tasks performance on acronyms resembled performance on pseudowords more than performance on words. To further assess the similarity of acronyms and words, we focused on the meaning of the acronyms and used masked priming to examine whether target words can be primed to the same extent with associatively related acronyms as with associatively related words. Such priming was possible at a stimulus onset asynchrony (SOA) of 84 ms. In addition, the priming of the acronyms did not depend on the letter case in which they were presented: The target word “books” was primed as much by isbn and iSbN as by ISBN.     

Exploring the time course of semantic interference and associative priming in the picture–word interference task

The picture–word interference (PWI) task is a widely used technique for exploring effects of semantic context on lexical access. In this task, printed words are superimposed over pictures to be named, with the timing of the interfering word relative to the picture systematically manipulated. Two experiments (N = 24 adults in each) explored the time course of effects of associates (e.g., CARROT superimposed on a picture of a rabbit) versus coordinates (e.g., CHIPMUNK superimposed on a picture of a rabbit) on naming latencies. Associates led to faster picture naming than did unrelated words, with facilitative effects occurring at stimulus onset asynchronies (SOAs, in ms) ranging from –450 to 0. Coordinates led to slower naming latencies, with the interference effect restricted to SOAs of –150 and 0. The overlapping time course of associative priming and coordinate interference provides important constraints on models of lexical access in speech production.     

Interference and the representation of order within associations

In the presence of interference, recall of pairs can critically depend on the diagnostic power of memory of the order of items within the pair. Models of pair memory make different assumptions about whether and how such order information is stored, from convolution-based models, which assume no explicit storage of order, to matrix models and several models that assume a pair is learned by concatenating the representations of the constituent items, which lead to perfect within-pair order memory (given retrieval of the pair). Here we investigate memory for associations and within-pair order by examining the relationship between forward and backward probes of pairs subject to order-dependent associative interference in a double-function list paradigm. Associative interference disrupted the high correlation between forward and backward recall accuracy that is typically observed in standard paired-associate learning, challenging matrix and concatenation-based models. However, participants could overcome some interference due to within-pair order ambiguity, challenging directionally ambiguous convolution-based models. Unexpectedly, the test–retest correlation was reduced for pairs under the influence of interference compared to control pairs. This finding is incompatible with all existing implementations of the model classes we consider. Any model must include an assumption that order encoding (but not retrieval) is unreliable, and the form of this additional mechanism may depend intimately on how a given model is designed. In sum, our findings suggest that within-pair order memory is neither poor nor perfect, pointing to a fallible mechanism for within-pair order learning in verbal association-memory tasks.     

The role of working memory capacity in multiple-cue probability learning

Multiple-cue probability learning (MCPL) involves learning to predict a criterion when outcome feedback is provided for multiple cues. A great deal of research suggests that working memory capacity (WMC) is involved in a wide range of tasks that draw on higher level cognitive processes. In three experiments, we examined the role of WMC in MCPL by introducing measures of working memory capacity, as well as other task manipulations. While individual differences in WMC positively predicted performance in some kinds of multiple-cue tasks, performance on other tasks was entirely unrelated to these differences. Performance on tasks that contained negative cues was correlated with working memory capacity, as well as measures of explicit knowledge obtained in the learning process. When the relevant cues predicted positively, however, WMC became irrelevant. The results are discussed in terms of controlled and automatic processes in learning and judgement.     

Differential impact of relevant and irrelevant dimension primes on rule-based and information-integration category learning

Research has identified multiple category-learning systems with each being “tuned” for learning categories with different task demands and each governed by different neurobiological systems. Rule-based (RB) classification involves testing verbalizable rules for category membership while information-integration (II) classification requires the implicit learning of stimulus–response mappings. In the first study to directly test rule priming with RB and II category learning, we investigated the influence of the availability of information presented at the beginning of the task. Participants viewed lines that varied in length, orientation, and position on the screen, and were primed to focus on stimulus dimensions that were relevant or irrelevant to the correct classification rule. In Experiment 1, we used an RB category structure, and in Experiment 2, we used an II category structure. Accuracy and model-based analyses suggested that a focus on relevant dimensions improves RB task performance later in learning while a focus on an irrelevant dimension improves II task performance early in learning.     

Evidence for a response preparation bottleneck during dual-task performance: Effect of a startling acoustic stimulus on the psychological refractory period

The present study was designed to investigate the mechanism associated with dual-task interference in a psychological refractory period (PRP) paradigm. We used a simple reaction time paradigm consisting of a vocal response (R1) and key-lift task (R2) with a stimulus onset asynchrony (SOA) between 100 ms and 1500 ms. On selected trials we implemented a startling acoustic stimulus concurrent with the second stimulus to determine if we could involuntarily trigger the second response. Our results indicated that the PRP delay in the second response was present for both control and startle trials at short SOAs, suggesting the second response was not prepared in advance. These results support a response preparation bottleneck and can be explained via a neural activation model of preparation. In addition, we found that the reflexive startle activation was reduced in the dual-task condition for all SOAs, a result we attribute to prepulse inhibition associated with dual-task processing.     

Are all letters really processed equally and in parallel? Further evidence of a robust first letter advantage

This present study examined accuracy and response latency of letter processing as a function of position within a horizontal array. In a series of 4 Experiments, target-strings were briefly (33 ms for Experiments 1 to 3, 83 ms for Experiment 4) displayed and both forward and backward masked. Participants then made a two alternative forced choice. The two alternative responses differed just in one element of the string, and position of mismatch was systematically manipulated. In Experiment 1, words of different lengths (from 3 to 6 letters) were presented in separate blocks. Across different lengths, there was a robust advantage in performance when the alternative response was different for the letter occurring at the first position, compared to when the difference occurred at any other position. Experiment 2 replicated this finding with the same materials used in Experiment 1, but with words of different lengths randomly intermixed within blocks. Experiment 3 provided evidence of the first position advantage with legal nonwords and strings of consonants, but did not provide any first position advantage for non-alphabetic symbols. The lack of a first position advantage for symbols was replicated in Experiment 4, where target-strings were displayed for a longer duration (83 ms). Taken together these results suggest that the first position advantage is a phenomenon that occurs specifically and selectively for letters, independent of lexical constraints. We argue that the results are consistent with models that assume a processing advantage for coding letters in the first position, and are inconsistent with the commonly held assumption in visual word recognition models that letters are equally processed in parallel independent of letter position.     

The Symbiosis between a Mother and Her Schizophrenic Son in a Group Therapeutic Process

Abstract

In psychoanalytical practice important, but less studied, transformative functions are performed by verbal comments which do not correspond to the classic model of mutative interpretations proposed by Strachey. The Authors describe some characteristics of such clinical situations, without coming into the better known categories of variations in technique. Such enunciations seem not to have a “strong”, (already clearly defined) meaning in the mind of the analyst, but contain rather a “weak” semantic potential, which can only develop with the active cooperation of the patient. In the light of these experiences, the Authors reconsider the general nature of psychoanalytical interpretation and emphasize the intersubjective and dialogical nature of the interpretive work carried out in analysis.     

Enactment effects and integration processes in younger and older adults’ memory for actions

The present study investigates the mental processes that are applied to previously attended items of working memory. In an object-switching task, participants counted the number of sequentially presented objects. In Experiment 1 the processing time increased when the object category switched from the prior trial compared to a repetition. More importantly, the further in the past the last instance of a current category was presented, the more processing time was necessary—an observation suggesting passive decay rather than inhibition of previously attended items. However, results differed when only two object categories were employed. Experiment 2 suggests that the lack of a clear indication of decay with small numbers of categories was due to participants’ expectancy of category switches rather than repetitions. Taken together, the results suggest that working memory items become less accessible the longer they have not been attended to, when strategic processes are controlled.