On the road to somewhere:

Brain potentials reflect language effects on motion event perception

Presented by Katie Steck

Flecken, Athanasopoulos, Kuipers, & Thierry 2015

Background Information

‘‘Users of markedly different grammars are pointed by their grammars toward different types of observations and different evaluations of externally similar

acts of observation’’ -Whorf, 1940/1956

Language Matters in Brain PotentialsThierry et al. (2009):

- Greek “ghalazio” and “ble” - light and dark blue- Greek speakers greater and faster perceptual discrimination between light blue and dark blue

Boutonnet et al. (2013):- English “cup” and “mug” v. Spanish “taza”- English speakers greater deviant-related negativity brain potentials than Spanish speakers

Using brain potentials, can you see similar language effects for motion?

How would language affect motion perception?

Grammatical Aspect- Grammatical category that expresses

how an action, event, or state (denoted by a verb), relates to the flow of time

-Perfective - bounded, no time inference- “I helped him”

-Imperfective - progressive (continuous, to be verb + _ing)

- “I was helping him”

Verb Form Influence

Anderson, Matlock, Fausey, and Spivey (2008):- Gave sentences either contain perfective or

imperfective past verb form.- Using a computer mouse, participants placed

character into a scene to match the description

Perfective Dropped character toward destination

Imperfective Dropped character at an intermediate point

Aspect and Non-Aspect languages

Aspect (English, Arabic, Russian, Spanish): Tend not to mention endpoints when not the

focus of the sentence.

- “A woman is walking” (perhaps towards something, but it doesn’t really matter what)

Non-aspect (Afrikaans, German, Swedish): Linguistic bias towards action goals and

motion event endpoints and dependent on perspective of viewer

- “A woman walks towards a building”

Language FocusLangacker (1987, 2008); Radden & Dirven, (2007):

Gave a scene where a person is walking along a road, with a house at a distance, but the clip ends before the person has gone anywhere near the house

-Describe this event“A person is walking”“A person walks to a house”

Focus on endpoint or the ongoing phase of event?

Aspect languages focus on processNon-Aspect languages focus on endpoint

Verbal interference can change results

Using brain potentials, can you see similar language effects for motion?

Experiment 1- Methods

Participants:20 English speakers (UK)20 German speakers (Netherlands)

Process:Animation first (1000 ms)Blank screen (200 ms)Target picture (600 ms)Blank screen between trials (800 ms)

Press a button if the picture exactly matches the preceding animation

Experiment 1 - Methods

492 Total Trials5% of animation-picture pairs full match (24 trials)

75% Full mismatch (372 trials)10% Endpoint match (48)

10% Trajectory match (48)

Hypotheses- Experiment 1

1. German speakers- Larger P3 in endpoint match than trajectory match

2. English speakers - Similar P3 in both endpoint and trajectory matches

3. Larger P3 amplitudes for full match conditions (both groups)

Experiment 1- Results

English - Peak at 520 msGerman- Peak at 610 ms

No significant difference in correct button pushes (90%)

Experiment 1 - Initial RM ANOVA Main Effects

Endpoint Match

Complete Mismatch

Po

siti

ve P

3 a

mp

litu

de

Full Match

Trajectory Match

p < .05 p < .05

p < .05 p < .05p < .001

p =n.s.

English and German groups similar pattern:

Groups were both attentive and motivated

Experiment 1- German Group

Higher P3 for Full Match than all others (p < .001)

Higher P3 for Endpoint Match than Mismatch (p <.05)

NS P3 difference for Trajectory Match and Mismatch (p <.05)

**Higher P3 for Endpoint Match than Trajectory Match (p <.05)**

Experiment 1- English Group

Higher P3 for Full Match than all others (p < .001)

Higher P3 for both Endpoint and Trajectory Match than Mismatch (p <.05)

**NS P3 for Endpoint Match than Trajectory Match (p =.073)**

Experiment 1- Interaction

Experiment 1- Results Summary

Groups were both attentive and motivated

German larger overall peak and slope, possibly explained by German group slower to reject partial matches

When there was significance, it was for more focus on the endpoint

- German group it lasted longer and differences between the mismatch condition only in the endpoint match condition, pointing to language differences in perceptual processing

Experiment 2- MethodsParticipants:15 English Speakers19 German Speakers

Process:Picture first (600 ms)Blank Screen (200 ms)Animation (1000 ms)Between trial (800ms)

- Match? Press “Yes” or “No” buttons, Response time and accuracy recorded

Fully randomizedEach picture (4) preceded by each animation (4) = 16 combosRepeated 10 times = 160 trialsAll together, 40 trials each of full match, mismatch, endpoint match, trajectory match

600 800

Experiment 2- Accuracy Results

No interactionNo main effect for groupMain effect of condition:

Did better correctly identifying mismatch than full matchNo difference between mismatch and endpointSlight difference between mismatch and trajectoryNo difference between endpoint and trajectory

Experiment 2- Reaction Time Results

No interactionNo main effect for groupMain effect of condition:

Reaction times fastest for mismatch trialsNo differences between critical conditions

Experiment 2- Correct “No” Button Results

No main effect for groupMain effect of condition:

Faster “no’s” for full mismatch than partial mismatchSignificant Interaction

German reaction times for partial mismatches slower than their reaction times for complete mismatchN.S. in English group

Experiment 2- Incorrect “Yes” Button Results

No interactionNon significant trend for group main effectMain effect of condition:

Accidentally pushed yes more often on partial matches than full mismatches

Experiment 2- Results SummaryGroups perform roughly the same in accuracy rates and speed of processing

Performance fastest and most accurate on full mismatch condition

Worse for both groups on the trajectory match condition (Language-independent bias for endpoints in motion (Slobin, 2006; Zacks & Tversky, 2001))

German reaction times slower for the partial mismatch than full mismatch (helps explain P3)

*Picture and motion pairing a non-verbal task*- Online verbal encoding strategies not likely*

The Point

German group had greater attention devoted to endpoints

English group had more equal attention devoted to endpoint and trajectory

Automatic processing for motion perception varies based on how you have experience coding things in your language

Limitations and Future Studies

Possibility of shape labeling-Correct in future research

Experiment 1 and 2 different people

Small sample size

Additional future research-Real world motion events

Fin

Extras

-Task processing and attention devoted to execution of task similar in Germans and English

-English P3 peak slighly earlier and shorter, less positive than German

-English and German similar in speed for detecting a full match

-Germans slower at rejecting partial matches

Extras

-Germans have a more positive P3 wave for endpoint match than trajectory match

- Endpoint processed with more attention and perceived as more relevant or salient than trajectory when matching animations with pictures

-English no sustained differences in P3 wave for endpoint match vs trajectory match

- No attentional bias, both elements similarly attended to