In the movieThey are robots,One robot in particular stood out. Sonny was different. He wasn't just sticking to his schedule; it displayed an emotional intelligence that other robots could not. Sonny wanted one thing he could never have: feel.
He could see and hear, but Sonny couldn't feel pain, taste ice cream, or smell the sweetness of a candle. The intricate and advanced sensory and perceptual processing that we humans have is extraordinary and sets us apart from others.
- What is sensory processing?
- What is Perceptual Processing?
- What are the stages of perceptual processing?
- How do sensory and perceptual processes work?
Sensory and perceptual processing
Without our senses, our brain has no access to the outside world.sensory processingenables the brain to receive external and internal stimuli. However, perceptual processing allows the brain to interpret the stimuli it receives.
You've probably heard about the five main senses: taste, smell, sight, touch and hearing. However, these are not the only types of sensory information the brain receives. Other sensory information the brain can receive could include balance and body position, blood control, and immune system control. The sense of touch also has subdivisions such as pain or temperature.
fg. 1 There are five primary senses: sight, taste, smell, touch, hearing, freepik.com
In order to receive the stimuli, we have several receptors that respond to them. These receptors include:
mechanoreceptors(mechanical stimuli, i.e. movement)
Sensory processing converts the stimuli we receive into language that the brain can understand.
First, the brain receptors receive a stimulus. Then, through a process called transduction, the properties of the stimulus are translated into nerve impulses. After that, special detectors analyze the properties of the stimulus and convert them into neural representations. The brain then accesses the previously stored information and compares it to the neural representation obtained. When the brain finally finds a "match," it can recognize and interpret the stimulus, beginning the process of perception.
Examples of sensory processing
Here are some examples of sensory processing before we get to the perceptual process.
- You put your hand on a hot stove and feel pain.
You feel hot while in a hot tub.
You light a candle and smell its fragrance.
You take a bite of spoiled food and it tastes bitter.
Once the stimulus information has passed through the stages of sensory processing and is now in a form that the brain can understand, interpretation begins. This process is calledperception process.There are two ways a stimulus can be perceived: bottom-up and top-down processing.
Bottom-up processing is the most basic form of processing and is primarily based on data.
upstream processingIt's when the brain relies on sensory information to perceive and understand the world.
For example, once the brain receives the sensory input that makes up the letter k, as long as the person has learned to read, the brain generally does not require higher mental processing to perceive that letter. Upstream processing is generally real-time. However, sometimes a higher level of mental processing is required for the brain to perceive sensory information. In this case,Processing from top to bottomnecessary
Processing from top to bottomIt's when the brain uses a higher level of mental processing of our past experiences and expectations to understand and perceive new stimuli.
During top-down processing, the brain cannot simply rely on sensory information for interpretation, but instead must use contextual cues. These cues may include other sensory information, past experiences, motivations, emotions, and cultural perspectives.
stages of the perception process
There are five stages in the perception process.
1)Stimulus- sensory information is received.
2)Organisation- The brain uses past experiences to make connections to familiar ideas and concepts. Ideas and patterns organize as the brain begins to understand what is happening.
3)interpretation/evaluation- Prejudices, emotions, motivations, and the environment begin to shape our interpretation of the information we receive, and we begin to assign meaning to them. Interpretation is subjective and will be different for everyone.
4)Storage- Our brain stores the event or moment in our short or long term memory.
5)Remember- The information we receive can trigger past events and moments in our brain and even recall stored memories without us realizing it.
fg. 2 stages of the perception process, StudySmarter Original
Difference between sensory and perceptual processes
|sensory processes||perceptual processes|
|Raw data is provided||shape our experiences|
Process by which the sense organs absorb information.
Process by which the brain receives and interprets sensory information
awareness of stimuli.
Interpretation of stimuli
Objective and subjective
Sensation ends where perception begins.
Perception begins where sensation ends.
It doesn't always lead to perception.
Always built by feeling
Limits of sensitivity in sensory and perceptual processing
Not all stimuli that surround us are processed sensorically. There is a minimum amount of energy that must be emitted for each stimulus to be detected.
Isabsolute thresholdrefers to the minimum amount of energy of a stimulus that must be delivered in order to be recognized half the time.
For example, what is the faintest light or the quietest sound that can still be heard 50 percent of the time? However, another theory suggests that detecting a signal may depend on more subjective factors.
Signal detection theorysuggests that stimulus recognition may depend on factors such as motivation, past experiences, or expectations.
Have you ever waited for a text message? You could swear you saw your phone turn onevery two minutes, only to find out you haven't received that message yet. Your expectations at that moment made you imagine stimuli that didn't exist. Or a mother is awakened by the faintest murmur of her newborn, but falls asleep during a noisy construction. Signal detection theory suggests that these events stem from past experiences, expectations, or motivations.
Some of the stimuli below the absolute threshold can still be received but are outside of our awareness. These are known assubliminal stimulior subliminal messages. While these messages are perceived, they do not go far enough to undergo perceptual processing, and therefore we are unaware of them. In other cases, after a stimulus is recognized, we can experiencesensory adaptationand be less sensitive to this stimulus over time. For example, our eyes get used to a dark room over time.
sensory adaptationIt is the phenomenon where sensitivity to a constant stimulus decreases over time.
Similar to the minimum amount required to detect a stimulus, a minimum amount of variation is required to detect a change or difference between two stimuli. This is known as thedifference threshold. For example, when you are in a dark room and your phone screen lights up. It would be easy enough to see that light. However, when you're in a bright, well-lit room, it's much more difficult to discern the brightness of the screen.
Ernst Weber took this concept one step further and found a specific relationship required to determine the difference threshold for each of our senses.
Weber's lawstates that for each of the distinct senses, two senses must differ by a minimum amount for a person to be able to tell a difference.
What happens in visual sensory and perceptual processing?
Like any other sensory stimulus, visual stimuli are received via receptor cells. These cells are the rods and cones. Once the rods receive the visual information, the light energy causes chemical changes that activate neuronal signals in the bipolar cells. The nerves of the ganglion cells are then activated and their axons form the optic nerve cords. The information pauses briefly in the thalamus but eventually reaches the visual cortex, located at the back of the brain in the occipital lobe. Once the visual cortex receives information, perceptual processing can begin.
fg. 3 The eye receives visual stimuli through its receptors, Pixabay.com
processing of visual perception
The brain employs various tactics to process the visual stimuli it receives. For example,Ffeature detectorsare nerve cells in the visual cortex that recognize certain characteristics of a stimulus, e.g. B. edges, angles, color, depth or movement. This feature allows us to recognize facial features. Or the brain can intervene in response to visual stimuliparallel processing.
parallel processingThe brain breaks down visual information into parts (movement, shape, depth, color) and assigns them to different areas of the brain for simultaneous processing.
Parallel processing explains a phenomenon calledblindnessPatients who have been injured may report not consciously seeing or experiencing visual stimuli, but may respond to them or later report them (SHAREet al., 2010). In addition, damage to other areas of the brain used during parallel processing can have other consequences, e.g. B. the loss of the ability to recognize movement or recognize faces.
Sensory and perceptual processing: key points
- TtranslationIt is the process by which the properties of the stimulus are translated into nerve impulses.
- upstream processingThe brain relies on the sensory information it receives to perceive and understand the world.
- Processing from top to bottomIt's when the brain uses a higher level of mental processing of our past experiences and expectations to understand and perceive new stimuli.
- The five stages of perceptual processing are:Sstimulation, organization, interpretation/evaluation, memory, memory.
- Isabsolute thresholdrefers to the minimum amount of energy of a stimulus that must be delivered in order to be recognized half the time.
- Weber's lawstates that for each of the distinct senses, two senses must differ by a minimum amount for a person to be able to tell a difference.