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Related Experiment Video

Updated: Feb 12, 2026

Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds

Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds

Published on: November 6, 2015

Agnosia for bird calls.

Louwai Muhammed¹, Chris J D Hardy¹, Lucy L Russell¹

¹Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.

Neuropsychologia

|March 25, 2018

Summary

This summary is machine-generated.

Semantic dementia impairs auditory knowledge, affecting bird calls and names. This study reveals that nonverbal auditory knowledge is organized in distinct parts, which can be selectively damaged in this condition.

Keywords:

Auditory agnosia Bird Semantic category Semantic dementia

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Last Updated: Feb 12, 2026

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Area of Science:

Neuroscience
Cognitive Psychology
Linguistics

Background:

The cognitive organization of nonverbal auditory knowledge is not well understood.
Deficits in environmental sound, word, and visual object knowledge are known in semantic dementia.
How auditory cognition breaks down in semantic dementia and relates to other knowledge deficits is unclear.

Purpose of the Study:

To investigate the impact of semantic dementia on auditory, visual, and verbal knowledge of a specific category (birds).
To assess the organization of nonverbal auditory knowledge and its relationship to other modalities in semantic dementia.
To explore whether auditory knowledge is fractionated and can be differentially affected in semantic dementia.

Main Methods:

Developed a novel neuropsychological test for avian characteristics (size, behavior, habitat) across auditory, visual, and verbal modalities.
Used a two-alternative-forced-choice procedure for knowledge assessment.
Compared a patient with semantic dementia to healthy controls with similar birding experience and assessed knowledge of human voices and faces.

Main Results:

The patient exhibited significant deficits in bird call and bird name knowledge but relatively preserved visual attribute knowledge.
Knowledge of human voices and faces remained intact.
In both auditory and visual modalities, knowledge of bird size and behavior was preserved, while habitat knowledge was deficient.

Conclusions:

Nonverbal auditory knowledge appears to have a fractionated organization.
This fractionated organization can be differentially targeted in semantic dementia.
The findings provide further evidence for the distinct organization of auditory knowledge.