Chapter 1

Chapter summary

Sensation and perception involve highly complex neural processes that consume a substantial proportion of the brain's cerebral cortex. Sensations (qualia) are primitive mental states or experiences induced by sensory stimulation. Perceptions are complex, organized, and meaningful experiences of objects or events.

Qualia can be divided into seven distinct sensory modalities. The modalities differ in terms of the physical stimuli that excite them, the neural structures involved in transduction and sensory analysis, and the functions they serve.

The three key elements of perception are: stimuli; neural responses; perceptions. Psychophysics studies the relation between stimuli and perceptual experience, whilst neuroscience studies the relation between stimuli and neural responses. Psychophysical linking hypotheses propose specific links between perception and neural responses. Psychophysical methods to study perception were developed by Weber and Fechner in the 1800s.

Cognitive neuroscience studies the parts of the nervous system which are involved in cognition using lesions, clinical case studies, single-unit recordings, neuroimaging, and direct brain stimulation. Computational neuroscience studies the computations performed by the nervous system, and the internal representations they create. The foundations of computational neuroscience were laid by the theories of three mathematicians: Alan Turing, Claude Shannon, and David Marr.