%% ### ==Todo== - [ ] Add from [[Psych]], chapter 7 - [ ] Give an example of vision: how sensation and perception work in that context - [ ] [[Learning and Memory]], ch 10, example of perceiving a cat - [ ] Luo, summary of chapter 5 on vision - [ ] Describe the relationship between perception and attention - [ ] [This article](https://study.com/academy/lesson/attention-perception-physical-psychological-influences.html) claims that perception follows attention. - [ ] https://www.perplexity.ai/?s=c&uuid=c9a75cc3-867b-4c67-b1a6-b1c7a4104476 - [ ] How are they different? - [ ] Do they occur simultaneously? Can they occur independently of each other? - [ ] Review [[Mindwandering]], which distinguishes between bottom-up and top-down processing - [ ] Add from [[Blueprint]]: The nature of nurture suggests an **active model of experience**: Genetic differences between people create **differences in how people experience their environment** and life events. The psychologically effective environment is the perceived environment — what we perceive about the environment is what we actually experience. The environment is not something "out there" that happens to us passively. Instead, we actively perceive, interpret, select, modify, and even create environments correlated with our genetic propensities. - [x] Add to Anki %% Perception is the **organization, identification, and interpretation of sensory information** in order to understand the environment.^[Schacter, 2011] It allows us to **make sense of the world**. ^[Weinstein et al., 2019] In contrast, [[Sensation is the process of collecting information about the world and converting it into neural signals|sensation is the process of collecting information about the world from sensory areas and converting it into neural signals]]. Perception involves the breakdown of sensory data and the assembly of information on both **conscious and unconscious levels**.^[Seel, 2012] Perception combines sensory input and prior experiences to create **subjective experiences**.^[Nathan, 2022; Seel, 2012] Perception is an **active search for useful patterns** rather than a passive recording of the environment.^[Seel, 2012] It is subjective, whereas sensation is objective (Weinstein et al., 2019). So different people will perceive the same situation differently, and even the same person might perceive the same situation differently at different times. The brain has access to two sources of information: memory and sensory input.^[Feldman Barrett, 2020] Related to these sources, there are **two kinds of information processing**:^[Weinstein et al., 2019] 1. **Bottom-up processing** is a type of perception that's entirely based on sensory input. It begins with the stimuli detected by the senses and then continues from one neuron to the next, until the signal reaches the highest level of the cortex.^[Lieberman, 2021] Bottom-up processing is passive, data-driven, "from the outside in", and happens in real time. %%An example is a newborn baby who doesn't yet have much prior knowledge and whose attention gets captured by loud and shiny objects in their environment.%% 3. **Top-down processing** is a type of perception that relies on a person's [[Memory is the capacity to encode, store, and retrieve information|memory]], which includes prior knowledge and expectations. Information that's available at higher levels of the cortex is used to guide processing at lower levels by interpreting the incoming sense data and filling any gaps. Top-down processing is [[The brain actively constructs subjective experience based on memory and sensory input|active]], conceptually driven, "from the inside out", and happens [[The brain constructs subjective experience predictively|predictively]], i.e., before sensory input reaches the brain. %%An example is reading a text and using one's prior knowledge to complete any gaps, e.g., where a word is hidden or missing.%% 1. Related: [[The brain is a prediction engine]] %%From [[How We Learn]]: **Top down assumptions (priors)**: Each brain module formulates hypotheses and sends the corresponding probabilistic predictions about the outside world to other regions, thereby constraining the assumptions of the next model. **Bottom-up messages (posteriors)**: In sensory areas, the model is confronted with reality. The brain calculates an error signal, which is the difference between the prediction and the observation. It serves to modify the internal model of the world to adjust it to reality.%% In short, **perception is a two-way process** of [[Perception is a process of guessing how to combine sensory input with prior beliefs|guessing how to combine sensory input with information from memory]]. Memory helps to reduce uncertainty when figuring out what's out there in the world. Sensory input serves to verify and correct the memory-based predictions about what's out there.^[Feldman Barrett, 2020] (See also [[Error feedback measures the difference between the expected and the actual outcome]].) Humans do a lot of top-down processing, which means that a person's prior experience has a large impact on their perception of the world.^[Weinstein et al., 2019] Past actions and experience shape current perceptions and thereby current actions and experience. In the same way, current actions and experience shape future perceptions and thereby future actions and experience.^[Feldman Barrett, 2020] Perception is often **incomplete and incorrect**. However, "the efficiency gains of favoring the most plausible interpretation outweighs the costs of occasionally getting it wrong".^[Bloom, 2023, p. 174] Relatedly: - [[The brain only needs to form an accurate model of the external world insofar as this increases the organism's chances of survival and reproduction]]. - [[Evolution by natural selection shapes our perceptions to guide adaptive behavior, not to perceive truth (Fitness-Beats-Truth Theorem)]]. - [[Perception compresses the complexities of fitness payoffs to bare essentials (data compression algorithm)]]. However, perception can also **improve with experience**. [[Perceptual learning consists of long-lasting changes in perception as a result of practice or experience that improve an organism's ability to respond to its environment]]. For example, the more you are exposed to a particular person, the better you become at recognizing them quickly.^[Lieberman, 2021] --- Created: [[2023-03-15]] Type: #permanent Topics: [[Learning (Index)]], [[Cognitive science]] Related notes: - [[What are the cognitive mechanisms of learning and how do they work?]] - [[Attention is the selection and amplification of sensory information]] - [[Error feedback measures the difference between the expected and the actual outcome]]