Cognition

Cognition comprises processes involved in acquiring, retaining, transforming and using information. Attention, human memory, language and reasoning describe overlapping areas of investigation rather than completely independent boxes. A single task can require several processes, so researchers compare conditions or FIT explicit models to distinguish their contributions. Cognitive neuroscience connects these behavioral distinctions to biological mechanisms. ^[ref]

Decision making is selecting an action or option from alternatives, using available information, goals and anticipated consequences. A descriptive theory asks how choices occur; a normative rule specifies how choices should be evaluated under stated assumptions. Choosing quickly, choosing accurately and obtaining a desirable outcome are different criteria.

Consider an invented choice between four guaranteed points and a gamble paying ten points with probability $1/2$ and zero otherwise. The gamble's expected value iswhich exceeds four. Maximizing expected points selects the gamble, but that rule alone does not establish how a person evaluates risk or values the outcomes. The example states a criterion instead of treating one choice as an automatic error.

Amos Tversky and Daniel Kahneman demonstrated that preferences could change when equivalent decision problems were formulated differently.^[ref] A useful experimental comparison holds consequences constant while changing their presentation. A resulting choice difference challenges an explanation based only on the listed outcomes, while leaving further questions about comprehension, goals and representation to be tested.

Spoken word recognition is the process of identifying familiar spoken forms from an unfolding speech signal and accessing the corresponding lexemes. It occurs as information arrives: the beginning of an utterance may fit several possible forms, while later sounds distinguish them. The temporary candidate set is a lexical cohort.

For example, the beginning of “candle” is also compatible with “candy”. As the later sounds arrive, the evidence changes. Recognizing the item therefore involves both sensitivity to the incoming sounds and access to stored phonological representations; it is not necessary to wait for a silent gap before beginning to interpret the signal.

A 2005 mouse tracking experiment made this changing evidence visible in action. Participants heard a target name while moving toward one of two pictures. A similar-sounding alternative altered the movement path even on trials ending at the correct picture. The result supported an account in which spoken word recognition can influence an ongoing action before the final choice is complete.^[ref]

The measured cursor path is a behavioural consequence of recognition, rather than a direct recording of a phonological representation. The inference linking the two must be made explicit.

A word's uniqueness point is the earliest point in its spoken form at which the sounds heard so far distinguish it from all competing words in a specified vocabulary. It connects a cohort model of spoken word recognition to the changing size of the lexical cohort.^[ref]

For an invented vocabulary, let three word forms be the phoneme sequences $pata$, $pana$ and $pita$, with spaces ignored and each symbol representing one phoneme. The third word becomes unique after $pi$, while the first two remain ambiguous after $pa$ and diverge at the following consonant. Uniqueness can therefore precede the end of a word.

This is a property of the chosen vocabulary and transcription, not a universal timestamp attached to a spelling. Adding another word beginning $pi$ changes the example. A word that is a complete prefix of another may require an end-of-word cue. Measured reaction time also includes perceptual, decision and motor processes, so it need not equal the lexical uniqueness time.

A mispronunciation detection task asks listeners to report an altered pronunciation in speech. The manipulation can vary where a change occurs within a word or how strongly the surrounding context predicts the word; responses can be scored for detection and reaction time.

In the 1978 spoken word recognition experiments, listeners in the detection condition saw the original passage while hearing it. The study compared this with a shadowing task, in which listeners repeated ongoing speech. Effects of syllable position appeared in detection, while contextual effects differed between the tasks.^[ref]

The written version supplies information unavailable to an ordinary listener without a transcript. Thus a quick correct response can reflect comparison with that text as well as processing of the incoming sounds. Keeping the altered sound, context and instructions explicit makes the task interpretable rather than treating detection accuracy as a pure measure of one isolated cognitive stage.

A shadowing task asks a participant to repeat incoming speech aloud while continuing to listen. The delay and accuracy of repetition provide behavioural measures of processing an unfolding speech stream. The task differs from repeating a whole sentence only after the speaker has finished.

William D. Marslen-Wilson and Alan Welsh used shadowing with altered pronunciations in continuous speech. Whether listeners repeated a changed form or fluently restored the expected word depended on aspects of the input and context. Comparison with a mispronunciation detection task helped show that task instructions change which influences appear in the measured response.^[ref]

A restoration is an observation about the spoken response. It does not alone establish that a listener consciously heard the original sound correctly, nor that every intervening processing stage had the same representation. This makes shadowing useful for testing the time course of spoken word recognition while keeping response production part of the explanation.

A cohort model explains spoken word recognition through an evolving set of candidate words, the lexical cohort. An initial stretch of speech activates plausible candidates; later acoustic evidence and, depending on the model version, contextual information constrain recognition. William D. Marslen-Wilson and Alan Welsh's 1978 study connected this account with experimental manipulations of continuous speech.^[ref]

For an illustrative English vocabulary, the opening sounds of “candle”, “candy” and “canister” initially overlap. Hearing the next consonant can remove “canister” while leaving the other two plausible; later sounds separate them. The candidates depend on pronunciation and the listener's vocabulary, not merely on matching written letters.

A deliberately simplified noise-free rule isHere $C_t$ is the candidate set after the evidence available at step $t$. This filtering illustration is not a fitted psychological model: noisy speech, graded activation and recovery from misleading evidence require additional assumptions. A uniqueness point concerns when the remaining acoustic prefix distinguishes a word within a specified vocabulary; it need not coincide with the listener's measured response time.

The original task comparisons motivate testing a model on intermediate behaviour and contextual effects, not just final accuracy.^[ref]

A lexical cohort is a set of candidate words compatible with an initial stretch of speech during spoken word recognition. In a cohort model, new acoustic information changes which candidates remain plausible. The term describes candidates in recognition, rather than a group of people followed in a longitudinal study.^[ref]

For an English example, an initial “cap” can fit “captain”, “captive” and “capsule”; later sounds distinguish them. The example assumes a particular vocabulary and pronunciation: spelling alone does not specify an acoustic cohort.

The 1978 experiments compared repeating ongoing speech with detecting altered pronunciations while following a written passage. Effects of where a mispronunciation occurred, and differences in the influence of context across tasks, constrained accounts of how incoming speech and prior expectations interact.^[ref] A candidate set is a model construct; behaviour supplies evidence about its time course rather than a literal inventory of consciously considered words.

Phonological competition occurs when speech forms with overlapping sounds are simultaneously plausible candidates during spoken word recognition and influence the eventual selection. For example, hearing the beginning of “candle” can make “candy” temporarily relevant as well. Later acoustic evidence can resolve the ambiguity even though the alternative has already affected processing.

In a 2005 experiment, a listener saw two pictures and used a mouse to select the named object. When the competing picture had a similar-sounding name, such as “candy” beside “candle”, the movement toward the correct object was drawn farther toward that competitor than toward an unrelated alternative. The comparison demonstrated an effect of phonological competition on the path of the response, beyond whether the final click was correct.^[ref]

This suggests a useful experimental distinction: accuracy measures the final choice, while reaction time and mouse tracking can reveal costs and intermediate influences. Similarity alone does not establish competition; a controlled manipulation must show that the alternative changes processing or behaviour.

Joint action is coordinated activity in which two or more individuals adjust their contributions in relation to one another to achieve an outcome together. The contributions need not be identical. Carrying a table, for example, requires complementary lifting forces and adjustments to a partner's timing and movements.

An illuminating contrast is between matching an external beat and coordinating with a responsive partner. Two people can follow the same metronome without responding to each other; in a duet, each may also anticipate and adjust to the other's timing. Distinguishing these arrangements helps identify what social coordination contributes beyond a shared stimulus.

One experimental approach distributes a task's responses between partners. In Natalie Sebanz and colleagues' 2003 study, a spatial stimulus-response compatibility effect appeared when a one-response task was performed beside a partner responsible for the other response, but not when it was performed alone. A single person performing both responses supplied another comparison.^[ref]

Such comparisons can test whether another person's possible actions enter an individual's planning. The shared setting and the mechanism producing coordination must be distinguished: merely placing two people in the same room does not identify how they organize their actions.

A family of accounts relating perception and action to predictions and incoming information. Explanations require a specified representation, error weighting and learning rule; the general vocabulary alone does not identify a mechanism.

The significance assigned to an event or experience. The same bodily sensation or reminder may have different emotional consequences depending on its meaning, while real-world danger still requires assessment.

Evaluation of coping possibilities, control and available responses. In appraisal theory, evaluating the same event as controllable or uncontrollable can help explain differences in emotion.

Evaluation of whether an event matters to well-being or goals, and whether it involves benefit, harm or threat. The distinction from secondary appraisal concerns evaluative content; it need not imply two consciously experienced, strictly successive stages.

Operations that select, transform, retain or use information. A definition broad enough to include all learning does not, by itself, identify a mechanism distinguishing one clinical disorder from another.

Creativity concerns production of ideas or products that are both novel and appropriate to a relevant purpose or constraint. A task asking for many uses of an object measures one form of idea generation, whereas evaluating a completed invention asks another question. Novelty, usefulness, fluency and originality therefore require stated scoring rules; a large count of responses need not mean that every response is valuable. ^[ref]

Improvement on a problem after an interval spent away from it. A causal effect of an interval condition does not by itself identify which mental events during that interval produced the improvement.

Reasoning uses information and relationships to form conclusions, explanations or decisions. Deductive reasoning asks what follows from stated premises, while probabilistic reasoning evaluates uncertain possibilities. The format of a problem can change performance without changing its underlying numerical relationships: expressing information as natural frequencies can make conditional relationships easier to track. This separates a person’s knowledge from the processing demands imposed by a representation. ^[ref]

Drawing a conclusion after comparatively limited evidence under a specified task. A beads task measures information sampling under particular demands, not a direct readout of every real-world belief process.

An information-sampling task in which observations from a source are used to infer which source generated them. Decisions about when to stop sampling can investigate reasoning tendencies, with comprehension and task incentives affecting interpretation.

Consciousness includes subjective experience and the conditions under which information is available to awareness. Scientific studies distinguish such questions from general wakefulness and from the accuracy of a verbal report. Metacognition measures aspects of evaluating one’s own performance, but a confidence score is not by itself a complete measure of experience. Separating behavioral access, self-evaluation and proposed neural mechanisms makes competing accounts experimentally clearer. ^[ref]

Awareness of oneself as the subject of an event located in personal subjective time. In Endel Tulving's account it characterizes episodic memory, as distinct from knowing facts without reliving their acquisition. An operational test of event information is not automatically a test of this phenomenology.^[ref]