Sensory Perception and Cognitive Processes in Humans and Animals
Psychology vs. Rationality in the Classical Sense
In the classical sense, philosophy that studies the soul cannot be considered a part of psychology or a scientific or experimental science. Experimental science studies behavior, which equates to what someone may do, whether observable or not.
Pinillos Text 1: Our way of seeing the world is not the only nor the best. For example, primate color vision sees colors located between red and violet. Stereoscopic vision means each eye sees a different image. Bird vision is more accurate for distance. There are insects that see colors invisible to us, and dogs hear sounds impossible for us to hear. Some animals have a comprehensive overview, seeing 360ยบ around them at the same time.
Gehlen’s Second Text: Considers the passionate life of the tick. The tick perceives the odor of light and temperature of mammals. It lacks eyes but can see light through its skin to navigate. It has a nose that only smells butyric acid. It has tactile sensations and can capture temperature.
Sensation and Perception
Sensation: The process by which our senses pick up sensory information (color, temperature, texture, forms, flavors).
Perception: The organization and interpretation of sensory information. Perception gives more meaning to sensations; we know what we are seeing. To perceive, two elements are needed: the object and the subject.
- Objective factor (stimulus): The change in energy emitted by objects that can be captured by a sensory receptor.
- Subjective factors: What the subject brings. The subject relativizes the perception. Two subjects receiving the same sensations can perceive different things due to prior knowledge, the physiology of the nervous system, needs and motivation, expectations, and emotional state.
Perceptive Schemas
Perceptive schemas: Refer to how we use our knowledge when perceiving.
Schema: Our knowledge is not dispersed but forms a structure. New knowledge is acquired when we can integrate it into the corresponding schema. Perceptual schemas are learned; we are not born with them. Acquisition changes with new knowledge.
Sensation as a Psychological Process
Sensation is a psychological process by which our senses register information from the external or internal environment. It begins when a sensory receptor is excited by a stimulus, sent to the brain through the nerve fiber, and once there, the recognition of sensory quality occurs. There are three phases: the excitation phase, the transmission phase, and the projection phase.
Phase 1: Reception of the Stimulus
The stimulus affects a sensory receptor (specialized cells for a certain type of stimulation):
- Taste buds: Chemical substances
- Olfactory rod: Chemical substances
- Touch: Pressure contact receivers
- Ear: Sound waves, hair cells
- Equilibrium: Gravitational force, hair cells
- Sight: Light waves, retina
Difference threshold: The minimum power between two sensations that allows us to recognize the difference. Thresholds are unique to each species and common to all members.
Phase 2: Transmission of the Nerve Impulse
In the sensory receptor, the nerve impulse is excited. Nerve fibers transmit electric current. There are two types of nerve impulses: sensory nerves (from the receiver to the brain, transmitting sensations) and motor nerves (from the brain to the muscles, allowing movement).
Perception Theories
Associations: Locke, Hume, positivism, and neopositivism consider perception an association of simple sensations. First, we receive sensations, and once they reach the cerebrum, this process produces perception.
Gestalt Theory: The German psychological school of the 1920s proposed that we first perceive an object and attribute a meaning to it. Once the object is perceived, we can analyze the image and break it down into the sensations.
General Law of Perception: We use it unless we do not perceive. It involves the distinction of figure/background.
Hallucinations and Illusions
Hallucinations: Perceptions without stimuli and no feelings (seeing or hearing something that does not exist). They have various causes.
Perceptual Illusions: Misperceptions due to a misinterpretation of stimuli. We see something that is there, but we perceive it incorrectly.
Memory and Forgetting
Memory: The ability to store and retrieve certain information (fixing, conservation, remembering). There are sensory, short-term, and long-term memories.
Forgetting: The natural disappearance of memory (permanent or temporary). Theories include:
- Theory of disuse: Affects mechanical memory.
- Theory of interference: Affects significant memory.
- Theory of repression: Psychoanalytic theory.
Amnesia: The disappearance of memories due to illness.
Imagination and Thought
Imagination: The mental capacity to build mental images.
Image: A representation that occurs in the absence of stimuli and meets the concrete and sensory characteristics of the object.
Thought: The capacity to elaborate and retain images.
- Concrete thought: Common to all animals. Thanks to concrete thought, we solve specific problems that affect a particular time.
- Abstract thought: Exclusive to humans. It is based on concepts and allows us to solve general problems. With a single solution, we can solve many problems.
Concepts: Mental, symbolic representations whose meaning is conventional. They refer to a set of objects. They are abstract, ignoring the concrete and sensory characteristics of the image or percept (intensional and extensional theories).