Pure optic ataxia and visual hemiagnosia – extending the dual visual hypothesis

Goodale and Milner's two visual system hypothesis is an influential model for the understanding of the primate visual system. Lesions of either the ventral (occipito‐temporal) or the dorsal (occipito‐parietal) stream produce distinct and dissociated syndromes in humans: visual agnosia is typical for ventral damage, whereas optic ataxia (OA) for dorsal damage. We studied the case of a 59‐year‐old left‐handed woman with a circumscribed lesion around the left posterior occipital sulcus, extending to the underlying white matter. Initially, she presented with a central visual field OA, which regressed to an OA to the right visual hemifield during the 3 months observation period. In addition, tachistoscopic experiments showed visual hemiagnosia to the right visual hemifield. In line with the findings of the neuropsychological experiments, the analysis of the structural MR data by means of a trackwise hodologic probabilistic approach revealed damage to the left superior longitudinal fasciculus and to the left inferior longitudinal fasciculus, indicating an impairment of both the dorsal and the ventral stream. The combination of OA and visual hemiagnosia in the same patient has never been previously described. The present case study thus provides further insights for the understanding of visual processing.     

Region-based shielding of visual search from salient distractors: Target detection is impaired with same- but not different-dimension distractors

Shielding visual search against interference from salient distractors becomes more efficient over time for display regions where distractors appear more frequently, rather than only rarely Goschy, Bakos, Müller, & Zehetleitner (Frontiers in Psychology 5: 1195, 2014). We hypothesized that the locus of this learned distractor probability-cueing effect depends on the dimensional relationship of the to-be-inhibited distractor relative to the to-be-attended target. If the distractor and target are defined in different visual dimensions (e.g., a color-defined distractor and orientation-defined target, as in Goschy et al. (Frontiers in Psychology 5: 1195, 2014), distractors may be efficiently suppressed by down-weighting the feature contrast signals in the distractor-defining dimension Zehetleitner, Goschy, & Müller (Journal of Experimental Psychology: Human Perception and Performance 38: 941–957, 2012), with stronger down-weighting being applied to the frequent- than to the rare-distractor region. However, given dimensionally coupled feature contrast signal weighting (cf. Müller J, Heller & Ziegler (Perception & Psychophysics 57:1–17, 1995), this dimension-(down-)weighting strategy would not be effective when the target and the distractors are defined within the same dimension. In this case, suppression may operate differently: by inhibiting the entire frequent-distractor region on the search-guiding master saliency map. The downside of inhibition at this level is that, although it reduces distractor interference in the inhibited (frequent-distractor) region, it also impairs target processing in that region—even when no distractor is actually present in the display. This predicted qualitative difference between same- and different-dimension distractors was confirmed in the present study (with 184 participants), thus furthering our understanding of the functional architecture of search guidance, especially regarding the mechanisms involved in shielding search from the interference of distractors that consistently occur in certain display regions.

     

Post-training intra-basolateral amygdala infusions of norepinephrine block sevoflurane-induced impairment of memory consolidation and activity-regulated cytoskeletal protein expression inhibition in rat hippocampus

Considerable evidence indicates that the noradrenergic system of the basolateral amygdala (BLA) participates in the consolidation of various types of emotionally arousing memories. We previously reported that administration of an anesthetic-dose of sevoflurane immediately after continuous multiple-trail inhibition avoidance (CMIA) training impaired memory consolidation. This experiment investigated whether posttraining noradrenergic activation of the BLA is sufficient to reverse the memory impairing effect of sevoflurane. Adult male Sprague-Dawley rats received bilateral injections of norepinephrine (NE 0.3, 1.0, or 3.0 μg/0.5 μl) or normal saline (NS 0.5 μl) immediately after training in a CMIA paradigm. Subsequently, the rats were exposed to sevoflurane (2% inspired) or air for 2h. Norepinephrine produced a dose-dependent enhancement of memory consolidation on a 24-h retention test. The highest dose of NE tested (3.0 μg/0.5 μl) blocked sevoflurane-induced impairment of memory consolidation and reversed the inhibitory effect of sevoflurane on activity-regulated cytoskeletal protein (Arc) expression in the hippocampus 2h after training. These findings provide evidence that the mechanism mediating the memory-impairing effect of sevoflurane involves a network interaction between the BLA noradrenergic system and modulation of Arc protein expression in the hippocampus.     

The sound of enemies and friends in the neighborhood

Previous studies (e.g., Pecher, Zeelenberg, & Wagenmakers, 2005) found that semantic classification performance is better for target words with orthographic neighbors that are mostly from the same semantic class (e.g., living) compared to target words with orthographic neighbors that are mostly from the opposite semantic class (e.g., nonliving). In the present study we investigated the contribution of phonology to orthographic neighborhood effects by comparing effects of phonologically congruent orthographic neighbors (book-hook) to phonologically incongruent orthographic neighbors (sand-wand). The prior presentation of a semantically congruent word produced larger effects on subsequent animacy decisions when the previously presented word was a phonologically congruent neighbor than when it was a phonologically incongruent neighbor. In a second experiment, performance differences between target words with versus without semantically congruent orthographic neighbors were larger if the orthographic neighbors were also phonologically congruent. These results support models of visual word recognition that assume an important role for phonology in cascaded access to meaning.     

Effect of the difficulty of prior items on the magnitude of judgments of learning for subsequent items

Research on metacognition often uses various kinds of paired-associate items (e.g., foreign language translation equivalents) to investigate judgments of learning (JOLs) under the assumption that the JOLs are made independently of each other. We tested this assumption by exploring the effect of manipulating the difficulty of prior Swahili-English translation equivalents to determine whether there is a contrasting change in the magnitude of the JOLs assigned to subsequent Swahili-English translation equivalents (e.g., intermediate-difficulty items might receive lower JOLs when following easy items than when following difficult items). The magnitude of JOLs for the subsequent items did not vary as a function of the difficulty of the prior items, even when there were 10 prior items of homogeneous difficulty that differed from the difficulty of the subsequent to-be-judged items.     

A model for evidence accumulation in the lexical decision task

We present a new model for lexical decision, REM-LD, that is based on REM theory (e.g., ). REM-LD uses a principled (i.e., Bayes' rule) decision process that simultaneously considers the diagnosticity of the evidence for the 'WORD' response and the 'NONWORD' response. The model calculates the odds ratio that the presented stimulus is a word or a nonword by averaging likelihood ratios for lexical entries from a small neighborhood of similar words. We report two experiments that used a signal-to-respond paradigm to obtain information about the time course of lexical processing. Experiment 1 verified the prediction of the model that the frequency of the word stimuli affects performance for nonword stimuli. Experiment 2 was done to study the effects of nonword lexicality, word frequency, and repetition priming and to demonstrate how REM-LD can account for the observed results. We discuss how REM-LD could be extended to account for effects of phonology such as the pseudohomophone effect, and how REM-LD can predict response times in the traditional 'respond-when-ready' paradigm.     

A longitudinal study of the relationship of maternal autonomy support to children's adjustment and achievement in school

A longitudinal study examined the relations of maternal autonomy support to children's school adjustment. Autonomy support and other parenting dimensions were measured when children were 5 years old. School measures were teacher-rated academic and social adjustment and achievement in reading and math in grade 3. Regression analyses controlling for age 5 family and child factors (e.g., socioeconomic status [SES], kindergarten adjustment, IQ) revealed that autonomy support was positively related to grade 3 adjustment (social and academic) and reading achievement. Maternal emphasis on school performance was positively related to achievement measures but negatively related to social adjustment. Maternal use of rewards and praise was unrelated to grade 3 school measures. Finally, supplemental analyses revealed that autonomy support was associated with greater consistency in children's adjustment across social and academic domains as well as higher overall adjustment. These results highlight the developmental significance of parental autonomy support in early childhood.     

Can infants attribute to an agent a disposition to perform a particular action?

The present research investigated whether 13.5-month-old infants would attribute to an actor a disposition to perform a recurring action, and would then use this information to predict which of two new objects-one that could be used to perform the action and one that could not-the actor would grasp next. During familiarization, the infants watched an actor slide various objects forward and backward on an apparatus floor. During test, the infants saw two new identical objects placed side by side: one stood inside a short frame that left little room for sliding; the other stood inside a longer frame that left ample room for sliding. The infants who saw the actor grasp the object inside the short frame looked reliably longer than those who saw the actor grasp the object inside the long frame. This and control results from a lifting condition provide evidence that by 13.5 months, infants can attribute to an actor a disposition to perform a particular action.     

Source consistency, distinctiveness, and consensus: the three dimensions of the Kelley ANOVA model in persuasion

Based on a conceptual analysis and existing research, the authors propose that the three source dimensions specified in the ANOVA model play similar roles in persuasion as other source characteristics (e.g., expertise). Two studies test assumptions derived from this approach regarding the effects of different combinations of consistency and consensus (Study 1) and distinctiveness and consensus (Study 2). Combinations resulting in contradictory (vs. similar) inferences regarding message validity should affect judgmental confidence and, consequently, affect message scrutiny. Study 1 shows that, as predicted, high consistency/low consensus and low consistency/high consensus (incongruent combinations) lead to higher desired confidence and more extensive message elaboration than high consistency/high consensus and low consistency/low consensus (congruent combinations). Similarly, Study 2 reveals heightened message scrutiny given incongruent (vs. congruent) combinations of distinctiveness and consensus. Results are discussed with respect to majority/minority influence processes and multiple source characteristics.