Formal Models and Cognitive Mechanisms of the Human Sensory System

1. Introduction

It is recognized that most human behaviors are triggered by external stimuli in terms of event-, time-, and interrupt-driven mechanisms. Therefore, human sensory receptors and derived sensations play a key role in explaining human behaviors and cognitive processes. Recent advances in cognitive informatics, neuroinformatics, and computational intelligence provide rational explanations for the human sensory system as smart interfaces between the brain and the external environment. There are five primary senses and seven perceptual senses that embody self consciousness inside the brain according to the Layered Reference Model of the Brain (LRMB) (Wang et al., 2006). The primary senses, such as those of vision, hearing, smell, taste, and touch, adopt physical or chemical receptors in order to transform real-world stimuli into uniformed electrical neurosignals in specialized neural pathways. The perceptual senses such as those of spatiality, time, motion, equilibrium, posture, attention, and consciousness (Smith, 1993; Pinel, 1997; Matlin, 1998; Westen, 1999; Reisberg, 2001; Wang, 2010b, 2012d, 2013a; Wang & Fariello, 2012; Wang et al., 2006, 2013c), generate complex and abstract sensational perceptions based on the primary senses.

• Definition 1:Sensation is a set of cognitive processes of the brain that interfaces the brain to the external world by sensory information detection, acquisition, interpretation, and processing.

Sensation is the Layer 1 functions of the brain as modeled in LRMB as shown in Figure 1 (Wang et al., 2006). The sensation layer of LRMB is a subconscious layer of the brain for capturing sensory information supported by the sensory receptors. Although most of the primary senses are subconsciously processed, the main mechanisms of sensory receptors, nervous systems, pathways, and corresponding memories can be rationally analyzed and modeled based on neurological, physiological, and psychological observations.

Figure 1.

The layered reference model of the brain (LRMB)

• Definition 2: The primary senses of the brain are physical and/or chemical stimuli of the real world directly captured by the sensory receptors such as those of vision, hearing, smell, taste, and touch.

Primary sensations are generated by the sensory neurons as sensory receptors.

• Definition 3: The perceptual senses of the brain are composed sensory that are derived based on synthesized primary senses, as well as the current internal consciousness status, such as those of spatiality, time, motion, posture, equilibrium, attention, and consciousness.