Lecture 6 Psycholinguistics Psycholinguistics Working memory The second

Lecture 6 Psycholinguistics

Psycholinguistics �Working memory �The second type of memory has been traditionally referred to as short-term memory (STM), and more recently as working memory (WM). Although the meaning of the words are similar, there is a subtle difference between them.

Psycholinguistics �The need for short-term storage is easy to state. The contents of the sensory stores are held for at most a few seconds, but many cognitive acts require that we hold onto information for longer periods of time. �Many apparently simple acts, such as solving problems in your head, mentally retracing a path after losing your keys, remembering the topic of a conversation after a distraction, etc. are in fact a complex series of decisions, and it is necessary to have a temporary holding place for intermediate decisions.

Psycholinguistics �Short-term memory is severely limited in size, or capacity; it can hold approximately 7 plus or minus 2 items of information. As a consequence, we cannot take in a string of digits such as 065848345071591918 and repeat it verbatim unless we reduce the strain on short-term memory. One way to do this is by chunking, in which we group individual pieces of information into larger units. �With a little practice, nearly everyone can learn to chunk a 18 -digit number into units such as 065848 -345 and 071 -591 -918.

Psycholinguistics �This arrangement is much easier to remember (at least for me, since these are the phone numbers of two of my children). �Working memory differs from short-term memory in that the term WM conveys a more dynamic view of memory processes. STM was usually viewed as a passive repository of information; WM has both storage and processing functions.

Psycholinguistics �+ The storage function is similar to the storage credited to short term memory: we hold on a limited amount of information for a limited amount of time. �+ The processing function is related to the concept of processing capacity. Processing capacity refers to the total amount of cognitive resources we may devote to a task (and this amount is assumed to be limited).

Psycholinguistics � Working Memory � Example 1. � Suppose you are asked to multiply 8 times 4 in your head. This would pose no problem. But if the numbers were 84 and 67, the task would be much more diffficult. Part of your processing capacity would be devoted to performing the arithmetic operations of multiplying 4 by 7, and part of this capacity would be needed to retain the result (28) in temporary storage while you multiply 8 by 6. � Ultimately, these two functions would be in conflict with one another, competing for the same limited pool of resources. � Working Memory � Example 2. � Alpha-span: words are presented in random order but must be recalled in alphabetical order.

Psycholinguistics Methodologies Behavioral Tasks �Many of the experiments conducted in psycholinguistics, especially earlier on, are behavioral inn nature �In these types of studies, subjects are presented with linguistic stimuli and asked to perform an action �For example they may be asked to make a judgment about a word(lexical decision), reproduce the stimulus, or name visually presented word aloud

Psycholinguistics �Reaction times to respond to the stimuli(usually on the order of milliseconds) and proportion of correct responses are the most often employed measures of performance in behavioral tasks. �Such experiments often take advantages of printing effects, whereby a priming word or phrase appearing in the experiment can speed up the lexical decision for a related target word later

Psycholinguistics �As an example of how behavioral methods can be used in psycholinguistics research, Fischer(1977) investigate word using the lexical decision task. �She asked participants to make decision about whether two strings of letter were English words �Sometimes the strings is actual English words requiring a yes response, and other times they would be non-words requiring a no response

Psycholinguistics �A subset of the licit words were related semantically while others were non related �Fischer found that related worse pairs were responded to faster when compared to unrelated word pairs �This facilitation suggest that semantic relatedness can facilitate or encoding

Psycholinguistics eye-movements �Recently, eye tracking has been used to study online language processing. �Beginning with Rayner(1978) the importance of eye movement during reading was established �Later, Tanenhaus et al(1995)used the visual word paradigm to stunt the cognitive processes related to spoken language.

Psycholinguistics �Assuming that eye movement are closely linked to the current focus of attention, language processing can be studied by monitoring eye movements while a subject is presented auditory with linguistic input.

Psycholinguistics Language production errors �The analysis of systematic errors in speech, writing and typing of language as it is produced can provide evidence of the process which has generated it

Psycholinguistics Neuromaging �Until the recent advent of non invasive medical techniques, brain surgery was the preferred way for language researches to discover how language works in the brain. �For example, severing the corpus callosum(the bundles of nerves that connects the two hemisphere of the brain) was at one time a treatments for some forms of epilepsy.

Psycholinguistics �Researchers could then study the ways in which the comprehension and production of language were affected by such drastic surgery �Where illness made brain surgery necessary, language researchers had an opportunity to pursue their research. �Newer, non-invasive techniques now include brain imaging by positron emission tomography(PET); functional magnetic resonance imaging(f. MRI); event related potentials(ERPs) in electrotranscranial magnetic stimulation(TMS).

Psycholinguistics �Brain imaging tech. vary in their spatial and temporal resolutions. �Each type of methodology presents a set of advantages and disadvantages for studying a particular problem in psycholinguistics.

Psycholinguistics Computational Modeling �Computational modelin--e. g. the DRC model of reading and word recognition proposed by Colt heart and colleagues--is another methodology. �It refers to the practice of setting up cognitive models in the form of executable computer programs. �Such programs are useful because the require theorists to be explicit in their hypotheses and because they are useful to generate accurate predictions for theoretical models that are so complex that they render discursive analysis unreliable.

Psycholinguistics �Another example of computational modeling is Mc. Clelland Elman, s TRACE mode of speech perception

Psycholinguistics Issues and Areas of Research �Psycholinguistics is concerned with the nature of the computations and processes that the brain undergoes to comprehend and produce language. �For example the cohort model seeks to describe how words are retrieved from the mental lexicon when an individual hears or sees linguistic input.

Psycholinguistics �Recent research using non invasive imaging techniques seeks to shed light on just where certain language processes occur in the brain �There are no. of unanswered questions in psycholinguistics, such as whether the human ability to use syntax is based on innate mental structures or emerges from interaction with other humans, and whether some animals can be taught the syntax of human language

Psycholinguistics �Two other major subfields o psycholinguistics investigates first language acquisitions, the process by which infants acquire language, and second language acquisitions �In addition, it is much more difficut for adults to acquires second languages than it is for infants to leran their first laguage. �thus, sensitive periods may existduring which language can be learned readily.

Psycholinguistics �A great deal of research in psycholinguistics focuses on how this ability develops and diminishes over times. �It also seems to be the case that the more languages one knows, the easier it is to learn more. �The field of aphasiology deals with language deficits that arise because of brain damage.

Psycholinguistics �Studies in aphasiology can both offer advances in therapy for individuals suffering from aphasia, and further insight into how the brain processes language.

Psycholinguistics phonetic �Phonetics is a branch of linguistics that comprises the study of the sounds of human speech, or—in the case of sign language– the equivalent aspects of sign. �It is concerned with the physical properties of the speech sounds or signals: their physiological production, acoustic properties, auditory perception, and neurophysiologic status.

Psycholinguistics �Phonology, on the other hand, is concerned with the abstract, grammatical characterization of system of sounds or signs. �The field of phonetics is multiple layered subject of linguistics that focuses on speech. �In the case of oral language there are three basic areas of studies:

Psycholinguistics 1. Articulatory phonetics: the study of the production of speech sounds by the articulatory and vocal tract by the speaker 2. Acoustic phonetics: the study of physical transmission of speech sounds from the speaker to the listener 3. Auditory phonetics: the study of the reception and perception of speech sounds by the listener

Psycholinguistics �These areas are inter-connected through the common mechanism of sound, such as wavelength, amplitude and harmonics.

Psycholinguistics History �Phonetic was studied as early as 500 BC in ancient India, with Pa. Gini`s account of the place and manner of articulation of consonants in his 5 th century BC treatise on Sanskrit. �The major Indic alphabets today order their consonants according to Pa. Gini`s classification.

Psycholinguistics �Modern phonetics began with Alexander Meliville Bell, whose Visible speech introduced a system of precise notation for writing down speech sounds.

Psycholinguistics Phonetic Transcription �The international Phonetic Alphabet is used as the basis for the phonetic transcription of speech �It is based on the Latin alphabet and is able to transcribe most feature of speech such as consonants, vowels and suprasgmental feature �Every documented phoneme available within the known languages in the world is assigned its own corresponding symbol.

Psycholinguistics: The Difference Between Phonetics and Phonology �Phonology concerns itself with system of phonemes, abstract cognitive units of speech sound or sign which distinguish the words of a language �Phonetics, on the other hand, concerns itself with the productions, transmission, and perception of the physical phenomena which are abstracted in the mind to constitute these speech sounds or signs

Psycholinguistics �Using an Edison phonograph, Laurimar Hermann investigated the spectral properties of vowels and consonants �It was in these paper that the terms formant was first introduced �Hermann also played back vowels recordings made with Edison phonograph at different speeds in order to test Willis` and Whaetstone` theories of vowel production

Psycholinguistics Relation to Phonology �In contrast to phonetic, phonology is the study of how sounds and gesture pattern in and across languages, relating concerns with other level and aspect of language. �Phonetics deals with the articulatory and acoustic properties of speech sounds, how they are produced and hoe they are perceived �As the part of investigation phoneticians may concern themselves with the physical properties of meaningful sound contrasts or the social meaning encoded in the speech signals.

Psycholinguistics �However the substantial portion of research in phonetic is not concerned with the meaningful elements in the speech signal �While it is widely agreed that phonology is grounded in phonetics, phonology is the distinct branch of linguistics, concerned with sounds and gesture as abstract unit and their conditioned variation(via , e. g. , allophonic rules, constraints or derivational rules)