Using experiential optimization to build lexical representations

To account for natural variability in cognitive processing, it is standard practice to optimize a model’s parameters by fitting it to behavioral data. Although most language-related theories acknowledge a large role for experience in language processing, variability reflecting that knowledge is usually ignored when evaluating a model’s fit to representative data. We fit language-based behavioral data using experiential optimization, a method that optimizes the materials that a model is given while retaining the learning and processing mechanisms of standard practice. Rather than using default materials, experiential optimization selects the optimal linguistic sources to create a memory representation that maximizes task performance. We demonstrate performance on multiple benchmark tasks by optimizing the experience on which a model’s representation is based.

     

Emotional conditioning to masked stimuli and modulation of visuospatial attention

Two studies investigated the effects of conditioning to masked stimuli on visuospatial attention. During the conditioning phase, masked snakes and spiders were paired with a burst of white noise, or paired with an innocuous tone, in the conditioned stimulus (CS)+ and CS- conditions, respectively. Attentional allocation to the CSs was then assessed with a visual probe task, in which the CSs were presented unmasked (Experiment 1) or both unmasked and masked (Experiment 2), together with fear-irrelevant control stimuli (flowers and mushrooms). In Experiment 1, participants preferentially allocated attention to CS+ relative to control stimuli. Experiment 2 suggested that this attentional bias depended on the perceived aversiveness of the unconditioned stimulus and did not require conscious recognition of the CSs during both acquisition and expression.     

Extraversion and emotional reactivity

Six mood induction studies and a meta-analysis were conducted to test 2 models of the extraversion-pleasant affect relation. The affect-level model suggests that extraverts should be happier than introverts in both neutral and positive mood conditions. The reactivity model posits that extraverts react particularly strongly to pleasant stimuli and that they should be happier than introverts only in positive conditions. In all studies, extraverts failed to exhibit greater emotional reactivity when pleasantness items were analyzed. When activated positive affect items were analyzed, results were mixed. The meta-analysis confirmed that there is only a slight reactivity effect overall, and this effect emerges only in activated positive affect items. Furthermore, the meta-analysis showed that the correlation in neutral conditions is strong enough to support the affect-level model.     

Dissociated developmental trajectories for semantic and phonological false memories

False recognition following presentation of semantically related and phonologically related word lists was evaluated in 8-, 11-, and 13-year-olds. Children heard lists of words that were either semantic (e.g., bed, rest, wake ...) or phonological associates (e.g., pole, bowl, hole ...) of a critical unpresented word (e.g., sleep, roll), respectively. A semantic false memory was defined as false recognition of a semantically related but unpresented word. A phonological false memory was defined as false recognition of a phonologically related but unpresented word. False memories in the two tasks showed opposite developmental trends, increasing with age for semantic relatedness and decreasing with age for phonological relatedness.     

Fear-relevant selective associations and social anxiety: absence of a positive bias

An illusory correlation paradigm was used to compare high and low socially anxious individuals' initial, on-line and a posteriori covariation estimates between emotional faces and aversive, pleasant and neutral outcomes. Overall, participants demonstrated an initial expectancy bias for aversive outcomes following angry faces, and pleasant outcomes following happy faces. On-line expectancy biases indicated that initial biases were extinguished during the task, with the exception of low socially anxious individuals who continued to over-associate positive social cues with pleasant outcomes. In addition to lacking this protective positive on-line bias, the high social anxiety group reported retrospectively more negative social cues than the low socially anxious group. Findings are discussed in relation to similar evidence from recent interpretive and memory paradigms.     

Interpretation of ambiguous information in clinical depression

The present study used two cognitive tasks--a text comprehension task and a homophone task--to investigate whether clinically depressed individuals have a negative bias when interpreting ambiguous information. Previous research indicates that both tasks are sensitive to anxiety-related interpretive biases, and that the former is less prone to response bias effects. Negative memory biases were also assessed. Results showed that, compared with normal controls, depressed individuals made more negative interpretations on the homophone task, and they also showed an enhanced negative recall bias. However, the groups did not differ in interpretative bias on the text comprehension task. Possible explanations of the results are discussed, including the potential influences of self-referent processing and response bias.     

Time course of attentional bias for fear-relevant pictures in spider-fearful individuals

The time course of attentional biases for spider stimuli was assessed in two groups of individuals with high or low levels of spider fear. Pairs of photographs of spiders and cats were presented in a visual probe task with three exposure durations: 200, 500 and 2000 ms. Results indicated greater attentional bias for spider stimuli in high fear, than in low fear, individuals in the 200 ms condition. The attentional bias in the high fear group significantly reduced as stimulus exposure duration increased, with no significant biases found in the longer exposure conditions. Results support the view that high fear is associated with an enhanced initial attentional bias for fear-relevant stimuli, but that this attentional bias is not maintained over time.     

Concurrent disjoint and reciprocal classification by Cebus apella in seriation tasks: evidence for hierarchical organization

We report the results of a 4-year-long study of capuchin monkeys (Cebus apella ) on concurrent three-way classification and linear size seriation tasks using explicit ordering procedures, requiring subjects to select icons displayed on touch screens rather than manipulate and sort actual objects into groups. The results indicate that C. apella is competent to classify nine items concurrently, first into three disjoint classes where class exemplars are identical to one another, then into three reciprocal classes which share common exemplar (size) features. In the final phase we compare the relative efficiency of executive control under conditions where both hierarchical and/or linear organization can be utilized. Whilst this shows a superiority of categorical based size seriation for a nine item test set suggesting an adaptive advantage for hierarchical over linear organization, Cebus nevertheless achieved high levels of principled linear size seriation with sequence lengths not normally achieved by children below the age of six years.