Directional Electrode

EQUIPMENT

in the Atlantic Bottlenose Dolphin (Tursiops truncatus ):

TIME (ms)

∞ “Ring-Cap & Tail” with 5 active

10 mm Ag/AgCl electrodes

∞ Synergy NPE5 amplifier & software

∞ Lubell EV-UW30 underwater

speaker

∞ Cetacean Research Tech SQ26-MT

hydrophone

∞ Device to hold speaker and

hydrophone in correct position

(1) Department of Psychology, University of Kansas, 1415 Jayhawk Blvd., Lawrence, KS, 66045-7556, USA; (2) Marine Mammal Behavior & Cognition Lab, University of Southern Mississippi, 118 College Dr #5025, Hattiesburg, MS, 39406-5025, USA; (3) ISPA, Rua Jardim do Tabaco 34, Lisboa, 1149-

041, Portugal; (4) Projecto Delfim, Centro Português de Estudo dos Mamíferos Marinhos, Rua Alto do Duque 45, Lisboa, 1400-009 , Portugal; (5) Communication Sciences & Disorders, University of Cincinnati Medical Center, 345A French East, 3202 Eden Ave, Cincinnati, OH, 45267-0379, USA

Dominie Madonna Writt (1,2), Patrícia Rachinas Lopes (3,4), Stan A. Kuczaj (2), Manuel E. dos Santos (3,4), Peter M. Scheifele (5)

Identification of Endogenous Event-Related Potentials

Applications for Communication Research

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Topography o f

component peaks

reflects interactions

between multiple

possible generator

sources and the

dipole dispersion

across various tissue

types.

Distance

above or

below the

baseline, or

between the

peak & the

trough . Can

reflect sum

resources.

Time

between

stimulus

presentation

& waveform

peak or onset.

Can reflect

processing

time.

NEURAL PROCESSING LEVELS

Exogenous ∞ Shorter Latency Components (<100-200 ms)

∞ Automatic Stimulus-Evoked Processes

∞ Valuable for Sensory System Research

∞ Relatively Well Established in Marine Mammals

Endogenous ∞ Longer Latency (>100-200 ms)

∞ Decision-Related Processes

∞ Useful for Information Processing Research

∞ Not yet established in Marine Mammals

METHODS RESULTS & DISCUSSION

“Ring-Cap”

Similar to method

used in human

multi-channel

ERP Research

Traditional Recording Method for Odontocetes

New Method:

Change Detection &

Information Processing

“The Classic P300”

(Properties for Human Adults)

∞ Positive central-parietal maximal waveform

∞ Peaks ~300+ ms following stimulus onset

∞ Amplitude inversely proportional to stimulus probability

∞ All properties influenced by stimulus value & complexity,

likely reflecting “Context-Updating” processes.

P300-like component recorded from Tursiops truncatus by

Woods, Ridgway, Carder, & Bullock (1986) using extracranial

electrodes over the skull, near the primary auditory cortices of

the suprasylvain gyrus (SSG).

COMMUNICATION: Further studies of these components could assist in the isolation and identification of marine mammal communication signals.

Odontocetes’ divergent & unique evolution may produce differences in neural processes between our species, but

convergent social behaviors may also have resulted in some unexpected similarities. This method could offer

insights into these phenomena.

N1-P2 Reflects simple stimulus detection

ERP

vent elated otentials

BACKGROUND

Placement System (suggested standardization for odontocetes)

Apollo (5 yrs)

Lotus (13 yrs)

Hugo (12 yrs)

SUBJECTS Gender: Male

Expand methods to investigate communication systems when overt behavioral responses are difficult to:

Can be combined with behavioral measures or reflect processes independent from overt behavior.

STIMULUS PRESENTATION:

“The Oddball Paradigm”

Tones (2, 4, 6, or 8 kHz*) 100 ms 85%-Standard 15%-Oddball

Silence as Oddball

2-4 Minute Random Blocks

1000 ms trace recordings

~50-traces/dolphin of each oddball assigned in random blocks over 3 wks.

*Tone frequencies were limited by stimulus

generating equipment. Data analysis of the

higher frequencies & complex stimuli pending.

Recording Parameters:

Band-Pass Filtered: 0.06-50 Hz

Artifact Rejection at 80 µV

(Only included averages >20% retention rate)

1-2 sec. random ISI

Video Behavior Monitoring before, during, & after program participation,

to assess any related behavioral responses, in the interest of dolphin

welfare. No negative response observed–pending analysis.

• Generate

• Interpret

• Time • Training

The Value of ERP for

Marine Mammal Communication Research

QUESTION

• Is there a reliable P300 like component in dolphins that is related to stimulus probability & found in the

processing latencies that could be sensitive to signal information value &

complexity?

• Based on previous research in humans, dolphins, and chimpanzees,

we expect such component to be identified within the 300-700 ms

latency range.

B. The 480-660 ms posterior positive component with a longer latency for the rare-tone condition, suggests -

that could be sensitive to processing complexity, relevant to future studies of communication.

Lines show significant

mean differences (p< .05)

FUTURE APPLICATIONS

A. The 120-260 ms component that differs in polarity & location by condition, suggests that the posterior negativity is specific to the processing of acoustic stimuli.

ALL CONDITIONS BOLD – Oddball (15%)

THIN- Standard (85%)

Comparison of Tone & No Tone (outlined)

Conditions

C. 720-760 ms anterior-maximal positive component only in the rare tone conditions, suggests a distinct component that reflects the integration of information provided by the deviant stimulus.

LOCATION (by Human 10-20 System)

Acknowledgments: Many thanks are due to Élio Vicente, Marco Braganca, and all the trainers and staff at Zoomarine (Algarve, Portugal) for their support and tireless efforts. Without their dedication, this project would not have been possible. Additional financial support provided by a KU honors fellowship to the first author and through U.S.

and Kansas State agencies. Thanks also to Joana Augusto for her invaluable support in stimulus recording, as well as equipment design, setup, and testing. Thanks to Jim Juola , Patricia Hawley, Andrea Greenhoot, Allard Jongman , and Michael Greenfield for their encouragement and advice in designing the project.

Please, feel free to contact to the first author at dominie@cetaceanscience.com with any comments, questions, or suggestions; also, if you are interested in discussing the potential application of ERP to your research programs.

TONE NO TONE

latency (ms) - 20 ms time windows) 100-300 300-700 100-300 300-700

subject

time X X

time * channel X X X

time * channel * probability X X

probability X X X

channel X

channel * probability X

100 160

760

560 620

OMNIBUS REPEATED-MEASURES ANOVA time (10 or 20) x channel (5) x probability (2) x subject (3)

1.5 sec. ISI

A

B

C

AM

PL

ITU

DE

(u

V)-

odd

ball-

sta

nd

ard

diffe

rences g

iven

-2.5

2.3

1.9

2.5

5.2

3.4

A1R3 -

A1L3 –

P2 - Tone

P2 -

P2 – Tone

A1L3 – Tone

A1L3 –

Oddball

Standard

If eye-to-naris (EN)

distance is 25 cm,

then 1 Placement

Unit is 2.5 cm

(10% EN).

SSG The current findings are important for establishing ERP components for use in answering

future, more complex research questions.

Table of Significant Mean Differences between Oddball

(15%) & Standard (85%) Component Amplitudes (µV)

Table of Significant Mean Differences between Oddball

(15%) & Standard (85%) Component Amplitudes (µV)