Monthly Archives: February 2015

Cowell at NSB Seminar Series Weds. 2/25 at 4 p.m.

Rosie Cowell (UMass Psychological and Brain Sciences) will be presenting Do amnesics forget because old things look new or because new things look old? in the NSB Seminar Series in 222 Morrill II at 4 p.m. Wednesday, February 25. Everyone is welcome – the abstract is below.

Abstract: I will describe a computational model of object recognition memory in perirhinal cortex (PRC) that provides a novel account of why damage to this MTL structure causes individuals to forget. The theory challenges the widely held assumption that the MTL is primarily a memory region. According to the theory, PRC is not a module for object memory, as assumed in most theories of amnesia, but rather a brain region that stores representations of the conjunctions of visual features possessed by complex objects. These representations allow PRC to engage in hyper-specific perception, enabling it to distinguish between particular objects that have been seen before (e.g., my blue Honda with a dent in the side) versus ones that have never been seen before (e.g., a blue Honda I have never seen before). It is this facility with hyper-specific perception that underlies the role of PRC in object memory. The model accounts for the classic findings concerning impaired recognition memory following perirhinal cortex lesions. In addition, it makes novel predictions, for example that brain damage causes a subject to forget not because familiar objects appear new, but because new objects appear familiar. I present simulation results demonstrating this novel prediction, along with findings from rats and humans that provide support for it.

Zuraw in Linguistics, Fri. 2/27 at 3:30 pm

Kie Zuraw of UCLA will be giving a job talk titled “Polarized Variation” (abstract below) in the Linguistics department on Friday, 20 February at 3:30 pm in ILC N400. All are welcome to attend.

Polarized Variation

The normal distribution–the bell curve–is common in all kinds of data, and is often expected when the quantity being measured results from multiple independent factors. The distribution of phonologically varying words, however, is sharply non-normal in the cases examined in this talk (from English, French, Hungarian,Tagalog, and Samoan). Instead of most words’ showing some medial rate of variation (say, 50% of a word’s tokens are regular and 50% irregular), with smaller numbers of words having extreme behavior, words cluster at the extremes of behavior–that is, a histogram of exceptionality rates is shaped like a U (or sometimes J) rather than a bell.  The U shape cannot be accounted for by positing a binary distinction with some amount of noise over tokens, because some items (though the minority) clearly are variable, even speaker-internally. In some cases (e.g., French “aspirated” words) there is a diachronic explanation: sound change caused some words to become exceptional, so that the starting point for today’s situation was already U-shaped. But in other cases, such an explanation is not available, and items seem to be attracted towards extreme behavior.

Two mechanisms for deriving U-shaped distributions will be presented, with some speculation as to why some distributions of variation are U-shaped and others bell-shaped.

Cox at Cognitive Brown Bag Weds. 2/25 at noon

Greg Cox of Syracuse University will be presenting A dynamic approach to recognition memory in the Cognitive Brown Bag series in Tobin 521B at noon Wednesday, February 25. He’ll be discussing a computational model of recognition memory that he developed with Richard Shiffrin that accommodates both response time and accuracy data. Everyone is welcome.

Dillon at Cognitive Brown Bag Weds. 2/18 at noon

Brian Dillon (UMass Linguistics) will be presenting Which noun phrases is this verb supposed to agree with… and when? in the Cognitive Brown Bag series in Tobin 521 at noon Wednesday, February 11. Everyone is welcome – the abstract is below.

Abstract: The study of agreement constraints has yielded much insight into the organization of grammatical knowledge, within and across languages. In a parallel fashion, the study of agreement production and comprehension have provided key data in the development of theories of language production and comprehension. In this talk I present work at the intersection of these two research traditions. I present the results of experimental research (joint work with Adrian Staub, Charles Clifton Jr, and Josh Levy) that suggests that the grammar of many American English speakers is variable: in certain syntactic configurations, more than one NP is permitted to control agreement (Kimball & Aissen, 1971). However, our work suggests that this variability is not random, and in particular, optional agreement processes are constrained by the nature of the parser. We propose that variable agreement choices arise in part as a function of how the parser stores syntactic material in working memory during the incremental production of syntactic structures.

Gallagher in Linguistics, Fri. 2/20 at 3:30pm

Gillian Gallagher of NYU will be giving a job talk titled Natural Classes in Phonotactic Learning (abstract below) in the Linguistics department on Friday, 20 February at 3:30 pm in ILC N400. All are welcome to attend.

Natural classes in phonotactic learning

The core representational unit in phonology is the feature, used to
define contrasts between sound categories (/i/ and /e/ are
distinguished by [±high]) and to pick out classes of sounds that
pattern together in the phonology ([+high] vowels may be restricted
from final position in some languages). Traditionally, phonological
features are thought to bear a direct relation to phonetic properties
(Jakobson, Fant & Halle 1952; Chomsky & Halle 1968). Under more recent
proposals, though, features are labels for phonologically active
classes that may bear a loose or no relation to the phonetics of the
sounds in question (Mielke 2008). In this talk, I present evidence
that phonetics plays a direct role in the natural classes used in the
phonological grammar.

The cooccurrence phonotactics of Quechua provide evidence for natural
classes grouping aspirated stops with the glottal fricative [h], and
grouping ejective stops with the glottal stop [?]. In addition to
being phonologically active, both of these classes are phonetically
definable based on articulatory properties of the glottis: [spread
glottis] picks out aspirates and [h], [constricted glottis] picks out
ejectives and [?]. Despite the phonological and phonetic support, two
nonce word tasks fail to find evidence for these natural classes in
speakers’ grammars. Instead, aspirate and ejective stops seem to be
targeted by the phonotactics to the exclusion of their glottal
counterparts. It is proposed that the preference for these smaller
classes of laryngeally marked stops is phonetically based, deriving
from the salience of the acoustic properties unique to stops.

Phonology search campus visits

The Department of Linguistics is currently conducting a search for a phonologist, and the campus visits have now been arranged. All of the candidates have interdisciplinary interests. Like all Linguistics colloquia, the talks will be held Fridays in ILC N-400, will be announced each week in this newsletter, and all are very much welcome. If you would like to meet with one of the candidates, please contact Joe Pater.

Gillian Gallagher (NYU): 19-20 February
Kie Zuraw (UCLA): 27-28 February
Eric Bakovic (UCSD): 5-6 March
Gaja Jarosz (Yale): 12-13 March

Sadil at Cognitive Brown Bag Weds. 2/11 at noon

Patrick Sadil (lab manager of Rosie Cowell’s Computational Memory and Perception Lab) will be presenting Visual Recollection in the Cognitive Brown Bag series in Tobin 521 at noon Wednesday, February 11. Everyone is welcome – the abstract is below.

Abstract: It is widely agreed that two processes – ‘recollection’ and ‘familiarity’ – contribute to performance on episodic recognition. Furthermore, these processes have been related to separate brain structures within MTL (e.g., Brown and Aggleton, 2001). However, we and others have proposed that both processes are carried out by multiple MTL sub-regions (Cowell et al., 2010; Diana et al. 2007) and what determines engagement of a given MTL region by either recollection or familiarity is the representational content of the memory (e.g., item/context/associations or spatial information). The Representational-Hierarchical (RH) view (Cowell et al. 2010) makes a novel prediction: recollection is a pattern completion process that may be computed by any brain region containing representations that could be used in the service of memory. We tested this prediction as applied to different kinds of visual representations (object, scenes, and object in scenes). For instance, if a subject encodes a visual object at study and is cued with part of the object at test, the RH view predicts that a pattern-completion process of recollecting the object (generating the whole from the part) should be carried out in object-representing regions (e.g., perirhinal cortex) without requiring hippocampal involvement. Behaviorally, this would amount to recollection in a non-associative memory task. We examined the behavioral effects of visual pattern completion using the process dissociation procedure (PDP) of Jacoby (1991). Following study, subjects were presented with a part of the studied item (an object part, a scene part, or an object that had been embedded in a scene): a visual analog of the word-stem completion task. They named the studied object or scene either by using (inclusion) or disallowing (exclusion) their memory of the study list. To avoid well-known aggregation biases with this procedure, we used the Bayesian hierarchical model of Rouder et al. (2008) to measure recollection and familiarity. Selective influence of an experimental manipulation was used to validate the use of the PDP; we found that recollection was greater for objects studied twice rather than once, whereas familiarity was unaffected by study frequency. These results provide evidence of visual recollection for objects. Future work will use these stimuli in an fMRI experiment to determine the brain locus of visual recollection for different kinds of visual stimuli.