Processing and use of sensory input. Measured discrimination and subjective sensory experience are related but distinct targets of explanation.
A task requiring selection of the different item among simultaneously displayed alternatives. Manipulating whether simple features or object-level conjunctions distinguish the odd item tests the representation required. Simultaneous presentation reduces long retention demands but does not eliminate all working memory or learned task rules.
A property of a discrimination in which an individual feature is compatible with more than one response, while combinations can disambiguate the stimulus. For example, learning that and are rewarded but and are not cannot be solved by assigning one fixed value to each feature alone. To prove the limitation for an additive threshold rule, suppose and , while and . Summing the first pair gives a total greater than , while summing the second gives the same total at most , a contradiction. Conjunctive representations can distinguish the pairs without this restriction.
A procedure in which another visual stimulus reduces access to a target stimulus. In backward masking the mask follows the target. Visibility must be evaluated under the relevant timing and task conditions; a short presentation by itself does not establish absence of awareness.
An experience of sound without an ordinary corresponding external sound source. The description does not by itself specify cause, clinical diagnosis or need for care.
An experience of a vOICe without an ordinary corresponding external speaker. Location, frequency, content, control, interpretation and distress are separable dimensions; the experience is not specific to schizophrenia.
A pattern in which discrimination or similarity depends on category boundaries beyond an appropriate physical or psychophysical baseline. Task demands, labeling and memory can contribute; boundary-related performance does not automatically establish a discontinuous sensory representation.
Category-dependent color discrimination, similarity or memory under a specified task. Cross-language boundary differences and prelinguistic category responses constrain different hypotheses and can coexist.
Perception of what objects are made of and their properties, including gloss, translucency, roughness and mechanical behavior. It depends on illumination, geometry, viewpoint and task as well as the material itself.
An appearance or optical behavior in which light is transmitted and scattered through a material rather than forming a clear transmitted image. Shape, thickness and illumination affect the available cues.
Variation of surface geometry over a specified range of spatial scales. Its optical effects depend on scale relative to wavelength and imaging resolution, material and illumination; perceived roughness is not a direct measurement of one universal roughness parameter.
A surface appearance associated with directional optical reflection and its image structure. Highlights, their relation to diffuse shading and their behavior across views can contribute; bright pixels alone are not a unique physical gloss measure.
Compatibility of highlight position and orientation with diffuse shading and inferred surface geometry. Controlled manipulations distinguish the relational cue from merely having bright pixels near a luminance maximum.
Processing of information about the body's internal state. Objective physiology, perception of that physiology and interpretation of its consequences are different variables.
Interpreting internal signals in relation to expectations and context. The same physiological change can receive different emotional interpretations; a computational account must specify testable predictions.
In one influential measurement framework, metacognitive correspondence between confidence and objective interoceptive performance. Other literature uses awareness more broadly, so the operational definition should be stated.
Self-reported beliefs, attention or experience concerning internal bodily signals. Questionnaire scores need not equal objective performance.
Performance on a specified objective test of detecting internal bodily signals. It is modality- and task-dependent; an accurate physiological recording does not guarantee a valid measure of conscious detection.
A task requiring judgments about the relation between external events and recorded heartbeats. Sensory timing and task calibration matter; it is not interchangeable with heartbeat counting.
A task comparing reported heartbeat counts with recorded beats over intervals. Prior heart-rate beliefs, timing strategies and bodily signal strength can contribute to the score.
A common score compares reported counts with recorded counts over intervals: . The absolute error is normalized by the recorded count. Equal reports give , but the score does not identify the reporting strategy. The unclipped expression is at most one and can be negative for sufficiently large overcounts.
Two strategies can generate the same observations: a person detects every beat, or a person estimates the count from an expected heart rate and the interval. Whenever the estimate equals the actual count, both produce and score . The score alone therefore lacks identifiability for the latent detection strategy. This logical counterexample does not say that all high-scoring participants use estimation.
Perception or estimation of one's heartbeat. A mental tracking score can depend on timing, beliefs about ordinary heart rate and response strategy as well as sensitivity to actual cardiac signals; such a score is not automatically a pure measure of interoceptive accuracy.[ref]
An unpleasant sensory and emotional experience. Pain should be distinguished from a stimulus applied by an experimenter and from an observer's inference that someone else is experiencing pain.
Reduction in pain, distinguished from sedation and from elimination of the underlying injury or disease. Drug exposure, expectation and prior experience can contribute through different mechanisms.
Access to information normally supplied through one sensory modality by recoding it for another. Successful use can restore a function without restoring the missing receptor system or establishing ordinary experience in that modality. Device engineering, learning and subjective reports address different aspects.
An apparatus capturing, transforming and presenting information through an available sensory channel. Evaluation must distinguish transmitted resolution from human recoverability, and laboratory identification from practical use.
A camera-to-sound sensory-substitution system developed by Peter B. L. Meijer. Its column scan encodes vertical position by frequency, horizontal position by scan timing and image brightness by amplitude. Later implementations add other cues; properties of one version should not be attributed to every prototype.
A rule converting image properties into acoustic features. One column-scanning example assigns vertical row to , horizontal column to scan time, and brightness to amplitude , yielding . Distinct orthogonal tones can preserve column coefficients in ideal conditions, while finite windows, masking and limited hearing resolution constrain perception.
Perception of position, direction, distance and spatial relations. Integrating cues can require transformations among retinal, head-centered and body-related coordinates, together with inference about whether the cues describe the same object.
Perception involving information from more than one sensory modality. A unified object report, changes in accuracy and a change in neural response are different observations, each requiring a stated experimental comparison.
A systematic association between attributes in different sensory modalities, such as pitch and visual size. It may influence matching, response compatibility or perceptual binding. Such an association does not by itself establish an additional synesthetic experience or multisensory fusion.
An association potentially mediated by shared pleasantness or affect. Manipulating pleasantness independently of the sensory relation helps distinguish a hedonic mediator from a direct sensory mapping.
An association mediated by shared meaning or labels across sensory attributes. Counterbalanced nonverbal responses and cross-language comparisons help test whether a common word is necessary.
A correspondence proposed to reflect learned co-occurrence or covariation of sensory attributes. A discriminating test changes the experienced relation while controlling exposure and tests transfer; a familiar pairing alone does not establish how it was acquired.
A proposed correspondence explained by organization shared across sensory dimensions or their neural codes. To distinguish this account from linguistic or learned environmental explanations, vary labels, task context and experience rather than identifying structure from agreement alone.
Interactions or combination of information across sensory modalities. Operational criteria must be specified: a neuron can show a changed paired response, a judgment can combine cues, or signals can be attributed to one event. These criteria constrain one another without being interchangeable.
A task-defined range of intersensory delays compatible with grouping or reported simultaneity. Its estimate depends on stimulus content, sensory uncertainty and decision criteria. It is not automatically the duration of one anatomical neural integrator.
An experience-dependent change in the intersensory timing relation judged simultaneous or used in binding. Exposure to a repeated audiovisual lag can shift later timing judgments. Transfer to a different task and recovery tests help distinguish calibration from a task-specific response strategy.
A combined response exceeding a specified unisensory benchmark. For baseline-corrected mean spike counts, defines enhancement over the strongest component. This differs from exceeding the sum, and depends on the response measure, analysis window and statistical comparison.
The tendency for relative multisensory enhancement to be larger when component stimuli evoke weak responses. Absolute gain and percentage gain must be distinguished: can increase merely because the denominator becomes small. A ratio is undefined at a zero denominator and does not directly measure information or behavioral benefit.
A combined response exceeding the sum of its separately measured component responses under an explicit baseline convention. Consistent subtraction of spontaneous activity prevents counting background twice. Enhancement above the strongest component need not be superadditive.
Inference about whether sensory signals have a common source or separate sources. Bayes' theorem compares hypotheses through . A common-source hypothesis can permit cue combination; separate-source hypotheses can preserve distinct estimates. Reliability weighting conditional on a common source is therefore not the entire causal-inference problem.
For a common-event model, let and with positive variances. The posterior exponent is . Completing the square yields posterior precision and mean . The estimate is pulled toward zero, more strongly when the measurement is uncertain. This conditional model does not decide whether a common event should be assumed.
Combining estimates or evidence from several sensory channels. Tests measure both the combined judgment and the uncertainty of the individual cues. A common-cause assumption should be tested rather than inferred merely from concurrent presentation.
A cue-combination rule weighting more precise estimates more strongly. For independent unbiased Gaussian estimates of one quantity and a flat prior, inverse-variance weights are both minimum-variance linear and maximum-likelihood weights. The assumptions exclude arbitrary averaging of complementary qualities such as odor identity and gustatory sweetness.
Let unbiased independent estimates have variances . The variance of is . Its derivative is and its second derivative is , proving the unique optimum and variance . Independent Gaussian likelihoods give the same estimate by differentiating . With covariance , the variance becomes , and the unconstrained optimum is when the denominator is positive; it need not lie between zero and one.
A family of phenomena in which an inducer elicits an additional experience or concurrent. Developmental examples often have involuntary, individually stable mappings, but their expression can be internally associated rather than externally projected. Definitions differ in breadth; ordinary multisensory integration, learned associations and unusual developmental concurrents should not be declared equivalent merely because all cross sensory or conceptual categories.
Integrated perception of food-related sensory information, including gustation, retronasal olfaction and oral somatosensory inputs. A unitary flavor or a mouth-localized experience does not uniquely identify the receptor system supplying each component.
Attribution or localization of an odor contribution to an object or event, especially food in the mouth. Mouth localization does not entail gustatory receptor transduction. Controlled route, attention and rating manipulations are needed to distinguish localization, quality and verbal labeling.
A perceptual grouping of acoustic components treated as belonging to a source or event. Harmonic relations, temporal coherence, location and learned expectations can contribute. A perceptual grouping need not correspond uniquely to one physical source.
A dependable relation between an action and its sensory consequences. A mirror generates tightly coupled visual changes that can support learning about the relation between body movement and reflected movement.
Experience considered from the experiencing subject's standpoint. Observable performance does not uniquely specify its qualitative character.
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Perception is the process by which individuals interpret and make sense of sensory information received from the environment. It involves the organization, identification, and interpretation of sensory stimuli, allowing people to understand and respond to their surroundings. Perception is influenced not only by sensory data but also by prior experiences, beliefs, cultural context, and psychological factors.