Biomedical subjects

Matthew J Pastizzo

Publications and source records attributed to Matthew J Pastizzo.

4 recordsLinked to original sources

PubMed2002

Multidimensional data visualization.

Historically, data visualization has been limited primarily to two dimensions (e.g., histograms or scatter plots). Available software packages (e.g., Data Desk 6.1, MatLab 6.1, SAS-JMP 4.04, SPSS 10.0) are capable of producing three-dimensional scatter plots with (varying degrees of) user interactivity. We constructed our own data visualization application with the Visualization Toolkit (Schroeder, Martin, & Lorensen, 1998) and Tcl/Tk to display multivariate data through the application of glyphs (Ware, 2000). A glyph is a visual object onto which many data parameters may be mapped, each with a different visual attribute (e.g., size or color). We used our Multi-Dimensional data Viewer to explore data from several psycholinguistic experiments. The graphical interface provides flexibility when users dynamically explore the multidimensional image rendered from raw experimental data. We highlight advantages of multidimensional data visualization and consider some potential limitations.

Data Display↗

PubMedDate not supplied

What do graded effects of semantic transparency reveal about morphological processing?

We examined the influence of semantic transparency on morphological facilitation in English in three lexical decision experiments. Decision latencies to visual targets (e.g., CASUALNESS) were faster after semantically transparent (e.g., CASUALLY) than semantically opaque (e.g., CASUALTY) primes whether primes were auditory and presented immediately before onset of the target (Experiment 1a) or visual with an stimulus onset asynchrony (SOA) of 250 ms (Experiment 1b). Latencies did not differ at an SOA of 48 ms (Experiment 2) or with a forward mask at an SOA of 83 ms (Experiment 3). Generally, effects of semantic transparency among morphological relatives were evident at long but not at short SOAs with visual targets, regardless of prime modality. Moreover, the difference in facilitation after opaque and transparent primes was graded and increased with family size of the base morpheme.

Decision Making↗

PubMedDate not supplied

Morphological processing: a comparison between free and bound stem facilitation.

Linguists distinguish between words formed from free stems (e.g., actor: act) and those formed from bound stems (e.g., spectator: spect). In a forward masked priming task, we observed significant morphological facilitation for prime-target pairs that shared either a free (e.g., deform-CONFORM) or a bound (e.g., revive-SURVIVE) stem. Relative to an unrelated baseline, magnitudes of facilitation for free (e.g., form) and bound (e.g., vive) stems were significant and comparable, but relative to an orthographic baseline free stem facilitation was greater than bound stem facilitation. In addition, the magnitude of bound (but not free) stem morphological facilitation correlated with the number of morphological relatives.

Decision Making↗

PubMedDate not supplied

When orthographic neighbors fail to facilitate.

Forward masked word primes that differed from the target in the initial, the final or both the initial and final positions tended to slow target decision latencies and there were no significant differences among prime types. After forward masked nonword primes we observed non significant facilitation when primes differed from the target by one letter in either the initial or final position and significant inhibition when primes differed in both initial and final positions. The patterns did not differ significantly for targets with large and with small neighborhoods. Only in post hoc analyses was there any indication of facilitation after nonword neighbor primes and it appeared only when body neighborhood was small. For slower participants, neighbors tended to facilitate target decision latencies while for relatively fast readers showed neighbors made inhibition that tended to vary with amount of mismatch.

Cognition↗