Understanding Perception and Hallucinations
Perception
Perception is a constructive process by which we grasp feelings and organize information into meaningful forms.
Key Features of Perception
- It is a constructive process depending on stimulus characteristics, personal experience, culture, and emotional state. Perception is conditioned by training, experience, personality, and culture.
- It is a process of information-adaptation to the environment. The goal is to make sense of reality, understand the world, and enable adaptation.
- It is a process of selection. Since incoming information is excessive and individual resources are limited, we perceive what is relevant. This selection, crucial for survival and adaptation, is driven by attention.
Stages of the Perceptual Process
- Detection: Each sense has a receiver, a group of cells sensitive to a specific type of energy.
- Transduction: The body converts one type of energy into another.
- Transmission: Sufficiently intense electrochemical energy triggers nerve impulses transmitting coded stimulus information to different areas of the brain.
- Information Processing: Sense organs detect and encode energy into nerve signals, but the brain organizes and interprets this information (e.g., as visual perception).
- Conscious Experience: Physical stimulation (e.g., electromagnetic waves) strikes the retina, is transmitted via the optic nerve to the occipital cortex, resulting in vision.
Hallucinations
Hallucinations are perceptions without an object. According to the sensory channel, they can be:
- Auditory: Experienced as noises, voices, or murmurs. These can be heard clearly or confusingly.
- Visual: Occur in people with brain disorders and in severe poisoning.
- Gustatory and Olfactory: Occur in some depressed and schizophrenic individuals who, influenced by their delusions, may smell poison or taste it in food.
- Tactile: Refer to skin sensations such as itching or stinging.
Attention: A Cognitive Process
Attention is a cognitive process that guides and controls conscious activity, enabling adaptive behavior. Attention is important not only because it orients our senses to perceive stimuli but also because it influences how we process information.
Some tasks allow for automatic processing, requiring little attention and making multitasking easier. Other activities require a controlled process involving significant effort and conscious behavioral control. (Example: preparing for an exam)