Functional organization of the rat amygdala with respect to avoidance behavior.

Bilateral electrolytic lesions in the periamygdaloid piriform cortex of female albino rats produced marked disruptive effects on the acquisition of active avoidance responses in a 1-way as well as a 2-way test situation, significantly impaired passive avoidance behavior, and inhibited feeding in a novel environment. Lesions in each of the 6 major subdivisions of the amygdala (cortical, medial, central, intercalated, lateral, and basolateral nuclei) consistently produced facilitatory effects on active avoidance behavior in 1-way as 2-way situations. Passive avoidance behavior was impaired in animals with lesions in the central, intercalated, and basolateral nuclei. Damage to the anterior amygdaloid area or the the nuclei of the lateral olfactory tract did not reliably affect active or passive avoidance behavior.     

Some effects of punishment on pain-elicited aggression

Painful mechanical tail-pinch elicited aggressive responses in paired rats; response-contingent electric shock to either forepaws or hindpaws suppressed fighting and stereotyped aggressive postures, including those in which dominance was expressed. There was no evidence that aggression was facilitated by shock that was contingent on pain-elicited aggressive responses. Aggressive responding recovered when shock was discontinued.     

Too much to count on: impaired very small numbers in corticobasal degeneration

Patients with corticobasal degeneration (CBD) have calculation impairments. This study examined whether impaired number knowledge depends on verbal mediation. We focused particularly on knowledge of very small numbers, where there is a precise relationship between a cardinality and its number concept, but little hypothesized role for verbal mediation. We evaluated accuracy and reaction time (RT) for matching dot arrays and Arabic numerals involving smaller (2-4) and larger (5-9) cardinalities in non-aphasic patients with CBD (n=16), frontotemporal dementia (FTD; n=23), and healthy controls (n=15). CBD were less accurate and slowed at judging smaller Arabic numeral-dot array stimuli compared to FTD patients and controls. Moreover, only CBD showed longer RTs judging successively larger number-dot array pairs among the smaller cardinalities. Difficulty judging very small numbers is impaired in CBD, suggesting degraded representation of precise number knowledge that does not depend on language functioning.     

Knowing who knows: Metacognitive and causal learning abilities guide infants’ selective social learning

Given the widespread interest in the development of children's selective social learning, there is mounting evidence suggesting that infants prefer to learn from competent informants (Poulin‐Dubois & Brosseau‐Liard, Current Directions in Psychological Science, 2016, 25). However, little research has been dedicated to understanding how this selectivity develops. The present study investigated whether causal learning and precursor metacognitive abilities govern discriminant learning in a classic word‐learning paradigm. Infants were exposed to a speaker who accurately (reliable condition) or inaccurately (unreliable condition) labeled familiar objects and were subsequently tested on their ability to learn a novel word from the informant. The predictive power of causal learning skills and precursor metacognition (as measured through decision confidence) on infants' word learning was examined across both reliable and unreliable conditions. Results suggest that infants are more inclined to accept an unreliable speaker's testimony on a word learning task when they also lack confidence in their own knowledge on a task measuring their metacognitive ability. Additionally, when uncertain, infants draw on causal learning abilities to better learn the association between a label and a novel toy. This study is the first to shed light on the role of causal learning and precursor metacognitive judgments in infants' abilities to engage in selective trust.     

The Experience of Religion and Spirituality Among College Students Who Use Illicit Substances

Nine collegiate illicit substance users participated in a phenomenological study of their perceptions of religion, spirituality, and substance use. We identified three themes from the interviews: (a) development of substance-using behaviors, (b) journey with religion and spirituality, and (c) intersectionality of substance use and religious and spiritual journeys. The participants voiced a complex bidirectional relationship among use behaviors, religion, and spirituality that could be facilitative, adverse, or divergent. We provide implications and suggestions for future research.     

Selective attention is a primary determinant of the relationship between working memory and general learning ability in outbred mice

A single factor (i.e., general intelligence) can account for much of an individuals' performance across a wide variety of cognitive tests. However, despite this factor's robustness, the underlying process is still a matter of debate. To address this question, we developed a novel battery of learning tasks to assess the general learning abilities (GLAs) of mice. Using this battery, we previously reported a strong relationship between GLA and a task designed to tax working memory capacity (i.e., resistance to competing demands). Here we further explored this relationship by investigating which aspects of working memory (storage or processing) best predict GLAs in mice. We found that a component of working memory, selective attention, correlated with GLA comparably to working memory capacity. However, this relationship was not found for two other components of working memory, short-term memory capacity and duration. These results provide further evidence that variations in aspects of working memory and executive functions covary with general cognitive abilities.     

Sentence processing in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative condition that is associated with the depletion of dopamine (DA)-containing neurons in specific brain regions. This article reviews one consequence of this defect-sentence comprehension difficulty in nondemented patients with PD. The first section describes the pattern of cognitive deficits seen in patients with PD, focusing specifically on their difficulties with language processing. Subsequent sections relate the profile of cognitive impairments in PD to studies investigating compromised DA metabolism in fronto-striatal brain regions. The findings suggest that the sentence comprehension deficit in PD is due in large part to limitations in the strategic distribution of cognitive resources such as selective attention that contribute to the processing of complex material. The physiological basis for this deficit appears to be associated with the disruption of a fronto-striatal cerebral network that is compromised following degradation of the DA projection system.