Fig. 2. Number of tamarins responding positively (white bars) and negatively (hatched bars) to test sentence depending on condition: language or speaker change, sentences played forward or backward. (A) Natural sentences. (B) Synthesizedsentences. (C) Data from experiments 2A and 2Bpooled together. *P , 0.05. **P , 0.01.

Fig. 1. Average number of high amplitude sucks per minute for babies in the control (speaker change, dotted lines) and experimental (speaker and language change, solid lines) groups. Minutes are numbered from the time of change. Error bars represent 61 SEM. (A) Natural sentences played forward. (B)Same sentences synthesized. (C) Same sentencessynthesized and played backward.

THE TORO ET AL. STUDY (RATS)

PEÑA ET AL (2003) Sounds and Silence: An OT study of language recognition.

If we had not worried so much about publishing this paperWe would have entiteled it “..speech processing.”

A few years ago we began to explore the brain neural substrate of speech processing by very

young infants.

We were interested in the FW vs BW discrimination andlateralization

To run the PNAS study we used a ETG 100 at aTrieste Hospital

Our procedure was as follows:

FW

BW

Sil

PLOT OF GRAND AVERAGE OF TOT.Hb (mmol/mm) OVER 5 SEC WINDOWS

After Marcela and her colleagues finished their workWe received an ETG 4000

This machine has channels separated by 2cm and weordered a set of probes with a 3cm distance

The wavelength between the machines was also modified

Shukla, Peña, et al. decided to replicate the PNAS results

Fw > Bw (at Ch7,8,911 of both Hemispheres) ; P <0.026)

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

The Shukla et al studies tend to be quite similar to theones we had observed in Trieste. However, the

results did not indicate that the LH (lower channels) respond more to FW than the homologous channels on the

RH

AN IMPORTANT DIFFERENCE BETWEEN BOTH STUDIESWAS DUE TO HOW THE PROBES WERE PLACED. IN

THE UDINE STUDY THREE PEOPLE PLACED PROBES WHICH WAS NOT THE CASE IN THE TRIESTE STUDY

A NEW REPLICATION WAS RUN WITH A VERY SMALL NUMBER OF INFANTS BUT WITH MARCELA PLACING

THE PROBES

p<0.05

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

.1

-.1-5 35

1 2 12

6 7

11 12

4 53

9 108

67

1112

45 3

910 8

Fw Bw Sil

LH RH

COLLABORATORS:

MARCELA MOHINISH

JUDIT AGNES