Resolving Cross-modal Semantic Interference among Object Concepts Requires Medial Temporal Lobe Cortex.

The ability to flexibly categorize object concepts is essential to semantic cognition because the features that make two objects similar in one context may be irrelevant and even constitute interference in another. Thus, adaptive behavior in complex and dynamic environments requires the resolution of feature-based interference. In the current case study, we placed visual and functional semantic features in opposition across object concepts in two categorization tasks. Successful performance required the resolution of functional interference in a visual categorization task and the resolution of visual interference in a functional categorization task. In Experiment 1, we found that patient D. A., an individual with bilateral temporal lobe lesions, was unable to categorize object concepts in a context-dependent manner. His impairment was characterized by an increased tendency to incorrectly group objects that were similar on the task-irrelevant dimension, revealing an inability to resolve cross-modal semantic interference. In Experiment 2, D. A.'s categorization accuracy was comparable to controls when lures were removed, indicating that his impairment is unique to contexts that involve cross-modal interference. In Experiment 3, he again performed as well as controls when categorizing simple concepts, suggesting that his impairment is specific to categorization of complex object concepts. These results advance our understanding of the anterior temporal lobe as a system that represents object concepts in a manner that enables flexible semantic cognition. Specifically, they reveal a dissociation between semantic representations that contribute to the resolution of cross-modal interference and those that contribute to the resolution of interference within a given modality.

Cultural differences in distraction processing: influence of context at retrieval.

Cultural differences in information processing affect perceptual judgment, attention, and memory. We investigated whether cultural differences in processing patterns, specifically East Asian participants' tendency to encode holistically, compared to Western tendencies to process analytically, affect performance on an implicit memory test. First, participants completed a 1-back task on pictures with superimposed distracting words. After a delay filled with a computerised Corsi block task, they performed a word fragment task in which some fragments could be completed with the distracting words from the 1-back task. Critically, fragments were presented with the same pictures as previously seen (matched condition), with no pictures (control condition), or with pictures from other trials on the 1-back task (mismatched condition). Non-Asian Canadian participants showed virtually no priming for distraction, independent of the reinstatement of encoding context. East Asian Canadian participants showed superior priming for fragments that had been paired with their original pictures. They did not show evidence of a detriment for the mismatched, relative to control, condition.

Foreground bias: Semantic consistency effects modulated when searching across depth.

When processing visual scenes, we tend to prioritize information in the foreground, often at the expense of background information. The foreground bias has been supported by data demonstrating that there are more fixations to foreground, and faster and more accurate detection of targets embedded in foreground. However, it is also known that semantic consistency is associated with more efficient search. Here, we examined whether semantic context interacts with foreground prioritization, either amplifying or mitigating the effect of target semantic consistency. For each scene, targets were placed in the foreground or background and were either semantically consistent or inconsistent with the context of immediately surrounding depth region. Results indicated faster response times (RTs) for foreground and semantically consistent targets, replicating established effects. More importantly, we found the magnitude of the semantic consistency effect was significantly smaller in the foreground than background region. To examine the robustness of this effect, in Experiment 2, we strengthened the reliability of semantics by increasing the proportion of targets consistent with the scene region to 80%. We found the overall results pattern to replicate the incongruous effect of semantic consistency across depth observed in Experiment 1. This suggests foreground bias modulates the effects of semantics so that performance is less impacted in near space.

Identifying compliance issues with prescription medicines among older people: a pilot study.

BACKGROUND: Older people are at greater risk from polypharmacy and adverse effects due to interactions and altered pharmacokinetics. They may also have greater difficulty managing their medicines and complying with dosage regimens for various reasons. OBJECTIVE: To identify the types of medicine compliance issues that occur among older people. METHOD: The study was undertaken in suburbs of the city of Auckland, New Zealand. A sample of 31 older people (> or = 65 years of age) living in the community consented to participate in the study. Semi-structured interviews and observation were used to determine how older people were managing their medicines. Observation of the interaction between the pharmacist and older person was performed to gather baseline information and semi-structured interviews were undertaken within 1 month to determine how older people were using their medicines and to identify compliance issues surrounding their use of medicines. Observation of the pharmacist-older person interaction was undertaken in the pharmacy where the older people usually collected their medicines, and participants were subsequently interviewed in their homes. The main outcome measure was compliance issues associated with the use of medicines. RESULTS: The main issues identified were alteration of labelled medicine instructions; transferring medicine into other containers and the associated labelling and safety issues; and patients not taking medicines for various reasons, including swallowing difficulties, expense, difficulty in opening packaging, confusion about the regimen and adverse effects experienced and personal reasons. There was an average of five compliance issues per participant. CONCLUSION: This study identified intentional and non-intentional compliance issues that could hinder the optimal use of medicines by older people who are at greater risk of medicine-related adverse effects. Large quantities of medicines, confusion, and lack of knowledge as to why a medicine had been prescribed contributed to non-compliance. Appropriate communication between the pharmacist and patient, patient education and aids such as medication cards and referral for medication review could improve compliance in this age group.

Integrative and distinctive coding of visual and conceptual object features in the ventral visual stream.

A significant body of research in cognitive neuroscience is aimed at understanding how object concepts are represented in the human brain. However, it remains unknown whether and where the visual and abstract conceptual features that define an object concept are integrated. We addressed this issue by comparing the neural pattern similarities among object-evoked fMRI responses with behavior-based models that independently captured the visual and conceptual similarities among these stimuli. Our results revealed evidence for distinctive coding of visual features in lateral occipital cortex, and conceptual features in the temporal pole and parahippocampal cortex. By contrast, we found evidence for integrative coding of visual and conceptual object features in perirhinal cortex. The neuroanatomical specificity of this effect was highlighted by results from a searchlight analysis. Taken together, our findings suggest that perirhinal cortex uniquely supports the representation of fully specified object concepts through the integration of their visual and conceptual features.