Category-Biased Neural Representations Form Spontaneously during Learning That Emphasizes Memory for Specific Instances.

Category learning, learning to sort a set of stimuli into categories or groups, can induce category biases in perception such that items in the same category are perceived as more similar than items from different categories. To what degree category bias develops when learning goals emphasize individuation of each stimulus and whether the bias emerges spontaneously during learning itself rather than in response to task demands is unclear. Here, we used functional MRI (fMRI) during encoding to test for category biases in neural representations of individual stimuli during learning.

Age effects on category learning, categorical perception, and generalization.

Age deficits in memory for individual episodes are well established. Less is known about how age affects another key memory function: the ability to form new conceptual knowledge. Here we studied age differences in concept formation in a category-learning paradigm with face-blend stimuli, using several metrics: direct learning of category members presented during training, generalisation of category labels to new examples, and shifts in perceived similarity between category members that often follow category learning.

Perceived similarity ratings predict generalization success after traditional category learning and a new paired-associate learning task.

The current study investigated category learning across two experiments using face-blend stimuli that formed face families controlled for within- and between-category similarity. Experiment 1 was a traditional feedback-based category-learning task, with three family names serving as category labels. In Experiment 2, the shared family name was encountered in the context of a face-full name paired-associate learning task, with a unique first name for each face.

Contributions of childhood trauma and atypical development to increased clinical symptoms and poor functioning in recent onset psychosis.

Aim: The trauma-psychosis cycle proposes an interactive relationship between impaired developmental and cognitive trajectory, childhood trauma exposure, and increased risk for psychosis. This study explored how childhood trauma (CT) and atypical development (AD) impact clinical course in an early psychosis cohort.

Methods: A retrospective chart review of behavioural and clinical research data was conducted with individuals ages 12 to 40 (N = 508; 72.

Clinical and neurodevelopmental correlates of aggression in early psychosis.

Background: Although mental illness accounts for only 4% of aggressive behavior in the general population, there remains a modest association between aggressive behavior and psychotic disorders, particularly in the early stages of the illness. However, little is known about the specific factors associated to this increased risk.

Aims: The present study aims to assess the rates, characteristics and risk factors of aggressive behavior in first episode psychosis patients (FEP).

Association of Age at Onset and Longitudinal Course of Prefrontal Function in Youth With Schizophrenia.

Importance: The extent of cognitive deterioration after schizophrenia (SZ) onset is poorly understood because prior longitudinal studies used small samples of older individuals with established illness.

Objective: To examine the association of age at onset and subsequent longitudinal course of prefrontal activity during the first 2 years of illness in youths with SZ and healthy control participants (HCs).

Design, Setting, And Participants: This naturalistic, longitudinal, functional magnetic resonance imaging (fMRI) study included patients with recent-onset SZ and HCs aged 12 to 25 years enrolled in an ongoing study of cognition in recent-onset psychosis in the Sacramento, California, area from October 13, 2004, through June 25, 2013.

Remembering and imagining differentially engage the hippocampus: a multivariate fMRI investigation.

It has been proposed that imagining the future depends on the ability to retrieve episodic details from past experiences in order to recombine them into novel possible experiences; consequently, the processes of remembering and imagining rely on similar neural substrates, including the hippocampus. We used fMRI and both univariate and multivariate analysis techniques to test this prediction. Unbiased univariate analysis did not reveal differences in the hippocampus between remembering and imagining; however, multivariate analyses revealed evidence that patterns of activity within the hippocampus distinguish between remembering and imagining.