Attention

• Attention acts as a means of allocating limited mental resources to information and cognitive processes at a given moment. ¹²

• Types of attention include:

  • Alertness and arousal: the basic aspects of attention that enable a person to extract information from the environment or to select a particular response. ²

  • Vigilance (sustained attention): the ability to sustain alertness continuously. ³

  • Selective attention: the ability to scan events/stimuli and pick out the ones that are relevant. ⁴

  • Divided attention: paying attention to two or more tasks at the same time. ⁵

Models of Attention

• Filter theories of attention postulate that there are certain 'filters' along the informational pathway that only allow certain information to pass through. ⁶

• Broadbent's early filter model suggests the filter takes place at the sensory level based on physical characteristics. ⁷

• Objections to the early filter model include the fact that unattended messages can sometimes be processed at a semantic level. ⁷

• Gray & Wedderburn's study showed that people can shadow based on meaning, not just physical characteristics. ⁸

• Treisman's model involves parallel pre-attentive analysis, pattern analysis, and focused attention. 【13,14】

• Deutsch & Deutsch's late selection model suggests all information undergoes analysis for meaning before selection. ⁹

Clinical Attention Deficits

• Neglect syndrome is the lack of attention to one side of space, usually the left, as a result of parietal damage. ¹⁰

• Bisiach and Luzzatti found that left neglect patients show a right side bias in their descriptions of memories. ¹¹

Sensation and Perception

• Sensation is the detection of physical energy, while perception is the process of organizing and interpreting sensory information. 【22,23】

• Visual perception involves light entering the eye, being focused on the retina, and stimulating photoreceptors (rods and cones) to produce neural impulses. 【24,25】

• The optic nerve fibers have receptive fields, and the LGN regulates neural information flow from the retina to the cortex. 【26,27】

• Bottom-up processing involves analysis from the stimulus to the cortex, while top-down processing uses contextual information. 【28,29】

• Perceptual organization follows Gestalt principles like similarity, proximity, continuity, and closure. 【31,32】

Auditory Perception

• Sound is a longitudinal pressure wave caused by vibration of material. 【33,34,35】

• The ear consists of the outer, middle, and inner ear, with the cochlea being the key structure for transducing sound waves into neural impulses. 【36,37】

• Tonotopic coding in the cochlea allows for the translation of frequency information into position along the basilar membrane. ¹¹